Hi Gordon, there isn't any method set up in MoI currently to analyze wall thickness like that. There isn't any function for that currently implemented in the geometry library that MoI uses and I'm not really sure how long it would take to develop it from scratch, but it's probably a pretty substantial project. I would not expect to be able to add that into MoI anytime soon, sorry.
I would recommend looking at some STL file checking software, there are some suggestions here: