I fully understand. Personally I cannot think of a more useful feature. I do hope that MoI continues to be developed purely as a streamlined, fast conceptual modeler, and doesn't branch off into other areas. It really has great potential to become the primary app for most industrial designers.

The benefits of every tool having history would be immense. I see Rhino has updated a lot of its tools with history - But I haven't used it in a while, so I don't know how advanced it is, or how well it's been implemented. I've no doubt you'll do a great job. An app with the ability to modify any past action (with live feedback), with a totally light and non-restrictive workflow, and a minimal UI, would be so perfect.

Best of luck! (and lots of hard work)