KoBeWi: Steam Workshop is supported, because Steam provides this functionality. GoG Galaxy doesn't have workshop in any form AFAIK.
However Lumencraft supports sharing maps directly. The map folder is available from main menu, you can easily copy the files around. There is an official Nexus Mods page where you can share maps. Also the Steam Workshop allows 3rd party downloads, so you can get the maps without using Steam.
Also to clarify, Steam Workshop is for now custom maps only (from the map editor). Lumencraft doesn't have official modding support and so there is no mod sharing via workshop. If this gets added, we'll make sure that GoG version will also support the same mods.
If you have any suggestions how the workshop support for GoG version can be improved, feel free to share.
PS
I'm a developer, but it's my first time using this forum.
Hi, thanks for a great game, and again, for the Linux support !
Today Steam Workshop allows 3rd party downloads (does it ?), tomorrow it doesn't - Valve breaking 3rd party tools that allow them already happened before, and it will happen again.
The issue is the normalization of platforms, especially of store-tied ones. (GoG Galaxy is slightly worrying in that too, I've heard that some GoG games now require it ? Still a far cry from the situation on Steam.)
There's a social aspect of it as well : if most people start using Steam Workshop (or, for other games, Steam online MultiPlayer, which is even worse), then hardly anyone will upload/download maps and mods to/from neutral places like their own websites, ModDb, Nexus Mods...