Does it really matter if they cross?

This is a question that's never occurred to me. My seed saving exploits have only come about since meeting the G&G group so I lack experience and very little had the chance to go to seed in my garden. The veges that were over had to be dug up to make room for the next lot. Logically, the variety crosses have been going on for eons, and if anyone was harmed by the resulting cross do you think we'd hear about it? I agree with SC, you're definitely elected to experiment (as you're doing) and tell the world.