Hi,
While I can see why you might want to do this, I can also see a situation of many many Sketches that Fusion
would need to keep track of and probably slow down the machine quite a lot. Sure the Sketch itself, when open,
would be nice and quick because it would be simple. At the same time, scrolling through a hundred simple
Sketches would not be fun and take ages on some machines.
You can still keep a Sketch simple and Extrude Multiple parts from it easily enough. If it then gets complicated,
simply Project the important bits and start a new Sketch. This works fine on simple or complex Projects. Think
about the difference between a simple One Cylinder Steam Engine and a complex High Performance Formula 1
Racing Engine. I could easily use your suggested method on the first one with no problems; I would be waiting
until next Racing Season if I tried to use it for the later case possibly.
I am sure the Gurus have an entertaining and valid reason to guide you here. As an Intermediate(?) user, I
think Keep It Simple Stupid works well, but not ALL the time.
Cheers
Andrew