So earlier today I was curious if custom objects will work with the new editor beta.
It is a bit annoying to do as currently you can add all the custom objects you want into the editors media folder, however when publishing the mod it doesnt automatically add the files to the _mod folder. All assets used will have to be manually entered into the _mod folder. After that when you publish it should send the additional assets to your workshop map.
My quick little test using the concrete lane dividers and a custom overlay found in the Russian .zip of a bunch of great additional assets.
Not sure if this was a fluke or what. But for custom objects try adding those objects into a downloaded mod truck files:
The tricky part is figuring out what numerical code is your MR install. Mine is 675010
I found adding folders into the mod .zip the game seems to run additional files without tripping the MP disable.
Although I have not tested after the update they released. I was trying to trick the mod maker into adding map files into a truck mod. It actually seemed to add some of the custom objects and such, but no luck with the .stg file.
If you want to run the game with zip files unpacked, you have to go into the "config" in the mudrunner main folder and remove .zip from the folders you wish to run unzipped.
So far seems to be working no problem without the zip. Only time I ran into an issue was opening mod maker to import the media files it searches for the zip folder.