Hi Eric, yeah I've thought some about getting a kind of automatic boolean built into Extrude.

It is somewhat more difficult to implement than it might seem at first, for example I can't just automatically do a union because if you extrude toward the other direction it should probably take away material like a boolean difference instead of union.

Also I'm not quite sure if it will be necessary to have an option for turning off "automatic boolean" or not.

So I don't think it is going to work to squeeze it into the end of v2 here where I'm trying to wrap things up right now. But it is a good candidate for a v3 feature.

There are 2 situations that I'm thinking of - the first one is when you extrude a face sub-object like you are talking about.

Then the other is if you extrude curves which are all currently contained within a face of a solid, that would be another good situation to have some kind of automatic boolean function. I've thought a bit before about making this case with curves to be triggered if you had selected the solid in addition to the curves, that could be the signal that you wanted to have the result of the curve extrusion booleaned with the solid automatically.

- Michael