while i understand yer reasoning for doing this and agree that it probably will give you more confidence while doing tougher moves, it sounds like taking an unnecessary risk, imho.
If you think that falling on gear on purpose is an unacceptable risk, then you should make damn sure you're climbing with the intention that the leader never falls. I mean, if you're pushing yourself on lead so much that a leader fall onto good gear is highly probable (and many people do this), then you should be just as willing to fall on purpose onto good gear in a controlled situation. Otherwise, well, you shouldn't be so willing to fall ever. IMO.
Personally, I would *never* fall on gear on purpose. But, I also would never lead a route where I thought it was likely that I would take a lead fall. But I'm a cautious leader and that limits my growth, I suppose. But, were I inclined to push my lead level to the point where taking lead falls was a common occurrence, then falling on gear on purpose shouldn't be that concerning of an event, should it?