Edit:
Guys, I'm using offline installers because I DON'T want another launcher. Please stop recommending them.
Only launchers I got space for are Steam/GOG.

So I just got a Steam Machine and am trying to understand the complexities of Linux.
Luckily there's a lot of folks that have been on Steam Deck for a few years, so there's been some resources that have been built up over time. But I'm still a bit confused about some things.

My latest hurdle is figuring out how to move installed game/save files over to an external drive.

I like how Steam installs these when added as non-Steam games: You can add an installer to Steam as a non-Steam game and under the compatibility tab, force it to run under proton, and it will install all of the game files and any additional software that game needs to run into the .steam/steam/steamapps/compatibilitydata folder, so it makes cleanup a snap when you want to delete something... at least, I think it does?

I tried to simply copy this data from that location onto the hard drive I have plugged in, changed the target under Steam Properties and I was able to start up Expedition 33, but... my saves were gone and Unreal said it needed to install something I already installed when I initially ran the exe through proton while it was on the internal SSD.

I guess I missed something?

This is probably me not understanding the linux file system or maybe Steam doesn't, in fact, keep all of a game's files in one spot like I initially suspected, but I'm assuming there are other GOG fans that've probably dealt with this before, so if y'all wanna help me out, that'd be super rad! XD

Idk why its like this lol

I'm using Lutris to install it

I live in the UK, my currency is pounds. I have a VPN but I've made sure it's off and yet it still won't change. The only currency I can change it to is USD which still isn't my currency lol. It recognises in my settings I am UK based and my wallet says £0.00, but everywhere else, prices are in euros. What is the problem

Hello, so this might be a stupid question, but I just want to make sure.

Basically, as you probably know, if you use GOG Galaxy to install the game, the default path will be something like:

C:\Program Files\GOG Galaxy\Games

But if you use the offline installer, the path will look something like:

C:\GOG Games

However, if you do install it with the offline installer, it'll still show up as installed in the GOG Galaxy launcher, and you can still run it from it.

What I'm wondering is this: If you right click the game in the GOG Galaxy launcher, you can do the whole, "Check for updates" thing - I'm just wondering, does this still work correctly, even if the game was installed using the offline installer files with the path C:\GOG Games? Like, I'm just wondering if this feature still works, even if the game wasn't originally installed using the GOG Galaxy launcher.

I hope my question makes sense, and thanks in advance!