Hi Curious, another thing which is probably getting in the way is that your objects are of a fairly large numeric scale and located a fair distance away from the origin.

Some of your strained surfaces are probably the result of some operation in MoI targeting a fitting tolerance of 0.001 units for the calculated result. When your objects are say 8000 units across that's really small in proportion to your object and that's probably why you've ended up with a heavy surface there.

It's better to keep your objects more around say 200 or so units across and positioned near the 0,0,0 origin point instead of a far distance away.

I've been on an ongoing process to try and make fitting tolerances relative to the object size instead of only fixed at 0.001 units to help with this but you're probably running across something that has not been converted to relative tolerances and your object size and position away from the origin are unusual so it's best not to do that. That's probably adding some difficulty to things.

- Michael