The dev support of the GoG version seem to me to be basically non-existent. Since the release there were two patches addressing some bugs and balancing changes. Unfortunatelly these went live only for Steam version and the GoG version didn't receive them. Can we expect receiving them here as well or are we left without it just because we bought the game on a platform of our choice?

It seems that the game has received the recent patch.

https://www.gogdb.org/product/1284626411#changelog

GOG really needs to list the patch history for games on the store page especially for in dev games.

It seems this game did receive the patch and I only know that because I own it and can see a patch available for it.

Any chance you could look at the patch notes and compare something in-game to see if they applied? https://steamdb.info/patchnotes/9794966/

This whole folder is still there
"Engine/Binaries/ThirdParty/OpenXR/"
And in the patch notes is states that has been removed.