So, I was fooling around, searching if there was a way to expand the resolution, when I saw that quite recently (like, literally some hours ago), there was an update. I don't know how GOG's staff operates about this stuff, but I though it would be nice for whomever is interested to search about it.

I wish I could find a changelog but I am too lazy to search the internet. I was personally hoping this forum would inform me as It has done previously.

You can find more infos on the official site of the game.

Here's the Changelog (v1.09) :
- It fixes the typing speed problem and the mouse interacting problem when the frame rate is too high.
- It allows you to use a better display aspect ratio on a wide screen monitor by using the resolution switching buttons on the main menu.
- It fixed a bug with the calculation of the local overall rating, which affects the average city overall rating.
- It fixed a bug with the display of the product rating bars on the firm detail screen, and a but with the firms report.
- It fixed a bug with jewelry and watch stores which may occur after loading a save game.
- It fixed a bug with the feature of your COO looking for better products."

It seems that you can download the patch from this site, and may be you can apply it manually to the GOG version.
There are good chances that GOG will include it by themselves in the future. But may be it could be a good idea to send a support ticket to bring this to their attention and being sure they are aware of it's existence.

Edit : Judas just confirmed that they updated the new version :)

Good news!

I've still got my fingers crossed for Cap Lab.