Hi, well it seems that i am not the only one that have the same idea with you, about a week ago i did the same and designed those chassis bolts only that i design it in tinkercad, not so sophisticated as yours, i made two sizes 1.2 and 1.1mm diameter and send them to a friend to print them for me. i am not sure about how strong will be either. I will follow your post with interest.
I am afraid i don't know how to upload an image here.
Thomas