I don't think it would matter either way. Though you would know the tree is healthy that you would be getting the bud from. That is more plant propagation than seed starting. That forum may have more advice on that topic.

I may be wrong here but in order to cross breed you must have 2 and the seed would be the result of the the cross not the bud. Also many apple trees need a pollinator in order to produce fruit, so for those types the only way you would get a true specimen to start would be plant propagation. Then you could cross, though your talking about years of a process here.