Almost everything on the web says mods don't work with XCOM 2 on GOG. But every now and then you come across someone who got it to work. Those threads are like 3 posts long with no followups.

But the threads that give instructions are almost all the same steps. So I tried again over the weekend. I still can't get it to work on my GOG version of WotC.
Those who do got it working, what am I still doing wrong?

This is my DefaultModOptions.ini file....

[Engine.XComModOptions]
ActiveMods=StopWastingMyTime
ActiveMods=LongWarOfTheChosen
ActiveMods="StopWastingMyTime"
ActiveMods="LongWarOfTheChosen"

Not sure to include quotes or not, have tried it both ways.

Have tried only one ActiveMods= line.
Ex - ActiveMods=LongWarOfTheChosen or ActiveMods=StopWastingMyTime

And tried it with quotes.
Ex - ActiveMods="LongWarOfTheChosen" or ActiveMods="StopWastingMyTime"

I have a folder StopWastingMyTIme and a folder named LongWarOfTheChosen inside E:\GOG\XCOM 2\XCom2-WarOfTheChosen\XComGame\Mods.
Both these folders have subfolders named Config, Script and Src. Additionally LongWarOfTheChosen has subfolders named Content and Localization.
They both have a .XComMod file also.

The game launches but the mods never load. Is there a step I'm still missing or should I just give up because its just not possible despite the occasional and rare internet thread from a random person who says they are using it with GOG?

A twist from my above post. I just downloaded Long War mod for the base Xcom2 game.
I copied it into E:\GOG\XCOM 2\XComGame\Mods. The extracted folder is called LW_Overhaul.
Then I modified the base Xcom2 DefaultModsOptions.ini file to include

[Engine.XComModOptions]
ActiveMods="LW_Overhaul"

With quotes. Now, when I launch the base game, there is an option to launch Long War. It starts my first mission with 8 soldiers in a suburb/neighborhood (instead of the typical 4 soldiers in a city needing to blast X4 on the advent). So I imagine this worked as it should. I retraced the exact same steps that allowed this to work into the XCOM 2 WotC but still running into the same issue where it launches WofC but no mods, and no options.

Getting closer now but still far away. Help please :).

I wrote my working piece in the past here.
So I can personally confirm it did work at least for me.

Also mods' order is usually also important as latter ones override former ones.
Thus I will recommend putting LongWar as the first one, due to being a huge overhaul.
Also it could have nuances to an installation process which should be mentioned in its description.

Thanks DawEdhel. After messing for a bit, the LW mod works great with the vanilla game so I've been enjoying that over the last day.
But now, when I launch WotC with mods (its a different config file, and a different mods subfolder - both in their own WotC\Xcomgame folders), and when I launch the WotC game, I now get a "Error detected load of package LW_Overhaul" message at launch and it crashes. Its definitely the WotC launcher (red color icon, all in the WotC install directory) so not sure why it appears to be pulling the mod instructions from the vanilla game.

I had looked at the thread you linked yesterday (in fact, it was one of the more helpful threads) . Both LongWar_overhaul and StopWastingMyTIme work well with vanilla. Following the same instructions but in different locations, LWoftheChosen and StopWasting do not work with the dlc. Googling seems to say the fix is downloading some highlander launcher which I'll mess with after finishing the LW_overhaul vanilla campaign,

Can you share the links where you've downloaded these mods?

The reason I'm asking is because as I remember there are supposed to be different mods' variants for both vanilla and dlc versions, e.g. every mod variant can be compatible only with single version unless mentioned otherwise.
And, as you've mentioned, your mods works well with vanilla, which are probably incompatible with wotc. For latter you need to find the proper variant one if it's available.

Yeah sure.

I downloaded from NexusMods the following mods..

LWOTC 1.0.1 (Complete package)-757-1-0-1-1640193800.zip (https://www.nexusmods.com/xcom2/mods/757?tab=files&BH=2)
Long War 2-633-1-5hf.zip (https://www.nexusmods.com/xcom2/mods/633?tab=files)
Stop Wasting My Time 1.1.0-217-1-1-0.zip (same general area in the Xcom 2 mods section for these other 3 mods)
EvacAll-WotC-99-1-1.zip
EvacAll-1.9-99-1-9.zip

The LWOTC was extracted into E:\GOG\XCOM 2\XCom2-WarOfTheChosen\XComGame\Mods
The Long War 2 zip was extracted into E:\GOG\XCOM 2\XComGame\Mods
Corresponding DefaultModOption.ini files were edited with appropriate lines into
E:\GOG\XCOM 2\XCom2-WarOfTheChosen\XComGame\Config and E:\GOG\XCOM 2\XComGame\Config respectively.

Since then I've found there is a DefaultModOption.ini file in C:\Users\....\Documents\My Games\XCOM2\XComGame\Config and C:\Users\....\Documents\My Games\XCOM2 War of the Chosen\XComGame\Config and those are saved the same as in the main installation folders.

So after playing LW_Overhaul in the vanilla game, it seems that's the only mod that seems to work though. The EvacAll is not working because I don't get that extra icon in game and soldiers still evac individually, and Central still chats thru the first few missions so StopWastingMyTIme doesn't work either. I've changed order of how the mods load but that doesn't seem to affect it since Overhaul is the only one that works in whichever spot it gets loaded.

Nothing works in WotC. Still get the "Error detected attempting load of package:LW_Overhaul" for some reason even though there is nothing in that ini file to tell it to load the Overhaul mod instead of the LWOTC mod.
Its pretty strange how only one mod works out of the 5-6 I've downloaded.

I have even uninstalled and reinstalled the game a few days ago before starting the vanilla Overhaul campaign. Might do this again once I finish this campaign or my best soldiers die off.
You didn't ask for this but just in case, I have these install files from GOG - setup_xcom2_war_of_the_chosen_374751_(64bit)_(35526), downloaded Novemeber/December timeframe and since it hasn't been updated in years, it has to be the latest files.

Thanks for your help btw, and hopefully I answered the question you were looking for.

I have a hypothesis that Long War 2 for vanilla game breaks mods by its own. From reading its description and development period time I've concluded that this mod is not aware of WotC at all and might be incompatible with newer game's structure after its global dlc update. Like it gets installed somewhere in shared environment for both game's variants.
To say for sure it's better to install only small mods on freshly installed game.

Have you read latest posts on NexusMods for this mod? There are some references for dedicated mod launchers, like Alternative Mod Launcher for XCOM 2. Maybe it has some vital inner checks on how mods should be added.

Also there are both installation and troubleshooting guides for both Long War 2 and LWOTC mods. Have you skimmed through them? There are some mentions about possibility of config corruptions which can be safely repaired.

Hey again. So I didn't install LW for vanilla until after LWOTC wouldn't launch for me. No errors or anything, just launched into WotC normally. What you say makes perfect sense because the errors didn't start happening with LWotC until after LW vanilla was installed and worked. But the game didn't recognize any mods when I tried them initially with that DLC.

I have read support threads here on GOG, Reddit and in Nexus - but that one has over 300 posts so I didn't get thru all when I started playing LW in vanilla. I've seen posts saying to install a 3rd party launcher, the one you mentioned and also something called Highlander.

I think what I'll do is keep playing LW in vanilla until I win, get tired of it (cuz its tough playing this base game now w/o all the extra WotC improvements) or get my ass kicked. After that, I'll uninstall everything cleanly and try again. Been watching some streams with LWOTC and it really looks so much more fun.

Thanks again for your diligence in trying to find a solution. Much appreciated :).

I'm planning one day in the future to check out these overhaul mods, at least after the stable and finalized release of LWotC.
So I would like to know beforehand about these kinds of problems and their found solutions.

I haven't gotten around to trying it yet, but *supposedly* the Alternative Mod Launcher works for non-Steam installs with what *sounds* like minimal work. Link to directions

Assuming that actually works then you could just grab the mods you want off Steam Workshop Downloader, extract those to your mods folder, point AML there and have everything working normally.

So very oddly, with nothing changed on my end, I loaded up the Long War Overhaul save I had been playing from the start (when I created this thread), and my EvacAll mod and StopWastingTime mod started working. I didn't even notice at first till my 2nd or 3rd mission where I saw the EvacAll icon. Then I noticed I hadn't heard command talk in the middle of a mission in this session.
I'm in September on this save so have been playing for a while. They didn't work yesterday and yet, today for the first time, it works. I'm not complaining but its quite odd.