I've searched for the answer to ths question and unable to find one..
Why would a person use sketch blocks, if your going thru the work
of sketching your part why not just extrude it and start modeling.
I come from Cadkey cad system and until I started to use SW and
some Autocad I'd never hear of this, aren't you doing twice the
skeching that's needed.
I'm not trying to be a smart butt, it's a serious question.