Larian could give you a better answer.

All good with offline installers, thank you. Really fast download speeds too.

Beta for Mac, not ok
paid for full version

It will work, but there's no point as it will need to download about the same thing. Larian warned us that there was too much difference between the Early Access and the final version to really take advantage of the update system.

1st this thread has really bad advice, guys don't update you gpu drivers until you know it's needed because that shit can be hard to roll back

2nd people that uninstall bg3 will get a popup asking if you also want to remove your data... Don't tick that box

Yes patching works fine... It's much of a muchness which way you go because gog put zero effort in and you will not save any download

If you decide to patch there are 2, 1st is 78mb and that is all the account unlocks then the 2nd is the same as doing a fresh install at 108g , be sure to restart Windows between these two patches

Why is that? What "data" does it remove?

Your Larian account info and system settings options

If you wiped that then when the new Larian launcher opens Goto account (top right) to sign in

Instead of typing user name and password click the gog logo them sign in with your gog username and password

Ahh. Don't have a Larian account so...

Why would you want to sign in with a Larian account anyway? It isn't required to play the game.

you sign in with Larian account to use cross saves but their sign in server busted about two minites into launch day so that is currently busted

another senario is muliplayer with Steam... once they get it running

as Larian launch days go this one is pretty good really

Larian's public date is September 6 for all platforms other than Windows.

Then I was right.

If we buy the full PC version on GOG now, will the Mac version automatically be available to us when it is released, or will the Mac version be a separate product? I just want to confirm before buying. Thanks.

GOG doesn't sell separate "PC Versions" or "Mac Versions".

You buy BG3 here, you get all versions.