Is there a way to add them instead of replacing existing objects?
@QBit07 Yes, like for example, my prop dino doesn't replace anything, it's just added to the game as a new prop. After exporting the customized prop from 3ds and making the ytyp in 3ds, the instructions for that mod are how I get custom things in the game all the time, and I have quite a few custom props I haven't released that I might start releasing. Do you have 3ds Max or the desire to use it? I only know how to do things the way I've learned along the way by tinkering with files and using 3ds to modify stuff. I could explain in more details how I made that custom prop if you would like to know, I might make a tutorial video soon.
I have it but don't really know how to use it. Got GIMS installed as well.