Bastecklein, do you have a function in your code that creates a building? If so, you might want to implement a way of creating new buildings in the Modding section.
Users could submit an .svg file with the artwork guidelines and submit all the details.
I love to give feedback and suggest new things!
if people could do this, they could create building that give them every resource possible very fast. maybe mods with added buildings could have a special tag, and that tag ether wont let them use it in online worlds, or disables all added buildings once coming back to an online world