I haven't played NWN2 in many years, but thought I'd give a Warlock another run as it was the first character I played.
However, as I said, I haven't played in years.
I recall a decade ago I was able to modify the game to let me get a new spell pick every level, but I can't recall how. This way I can experiment with the spells again as I don't recall what build I liked and I don't care about being OP, I want to have fun.
I'm almost certain I used a 2DA file in the override folder.
However, over the last decade, I went from using the DVD version with MotB to purchasing the GoG version when it was on sale in order to get the Storm of Zehir expansion and the premium modules.
I think I might have the old version installed on a backup of my Vista/7 computer, but the GoG version is installed on my Win10 computer, and I don't see any 2DA files in the override folder, only a bunch of .NCS files. Apparently when GoG removed the copy protection they also recombined the expansion packs instead of relying on the override folder.

NearInfinity doesn't appear to support this version of NWN2 and neither does InfinityExplorer. I don't see anything about viewing 2DAs in the Toolset.
What tool would I have used to browse NWN2 2DAs, identify and modify the .2DA file for Warlock spell progression? This would be simple with either of the two mentioned editors in the Infinity Engine games, and I know I didn't have this much trouble a decade ago.

I am embarrassed to ask, but I couldn't find the info in 5 minutes of Googling and just want to relax right now so I thought I'd ask here where somebody can probably answer off the top of their head.
About the closest I could find to an answer was this:
https://forums.nexusmods.com/index.php?/topic/6528841-editors-similar-to-inifinty-explorer-or-near-infinity/

You only put the 2DA files into the override folder after you edit them.
You will find them in ...\NWN2 Complete\Data folder in 2DA.zip.
You can use TLKEDIT2 https://neverwintervault.org/project/nwn2/other/tool/2datlkgff-editor-aka-tlkedit2 In the toolset you press Alt V and then 2
Or View > 2DA (See pics)
I'd guess you want the classes 2DA, but this isn't something I usually do, so I'm not sure.
If you can't work it out, ask on the vault. kevL_s knows everything.
https://forum.neverwintervault.org/c/nwn2/6

Edit: It's not letting me attach the pics at the moment.

For some reason Win10 saves extensions (png, jpg, etc in caps PNG, JPG, etc) and GOG does not seem to accept that, which is really an odd thing. I only know it since I ran into this issue and some helpful forum users provided the answer.

If indeed your issue was related to that. If not, ignore this reply. :)
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In the toolset, if you click on "Help" > About. It will tell you the version 1.0.1765.0 was the final version.

If you click on the little down arrow at the end of the toolbars to show "Add and Remove Buttons" Is it in the list that is not checked. (See Pic)