How do I get a model to quit rebuilding while I'm still in a sketch?

When I need to go back and modify geo in a sketch or change a line from regular geo to construction geo, all of the following features after that sketch will rebuild (and sometimes fail before I complete the change to the sketch) when I change it to construction geo.

It's REALLY affecting my productivity, as I use some decently complex aesthetic type surfacing, usually involving complex rather than simple sketches, and if the sketch is early on in the part it will rebuild the thing all the way down the line to my rollback point. It sometimes takes FOR-EV-ER, especially if I have to do it multiple times before exiting a sketch.

I cant find an option on this anywhere. I've got Instant 3D turned off because it turned Solidworks into a snail. Other than that I cant find any options that seem to relate to this.

Can someone clue me in here please?