I would like to use this for 3D printing. I often find that I need to go back and modify features because the size didn't come out correctly. Lets say a partial hole is formed by some boolean operation where the subtraction wipes out the tool.
My question is it possible to go back and modify sizes that are not shown in the final model? its seems inefficient to undo to that point & rebuild the model from there. so the question is how to you get around not having history?

I attached the model in question.