I think he should be used exactly how he has been used... give him minutes early in the series, see what he gives you, and then make your decision based on that.
During all the series so far, Leon has gotten plenty of minutes during the early portion of the series, and for the most part he has dissapointed or been too inconsistent to be counted on at a regular basis. I expect Doc to extend him the same sort of curtesy, but with a shorter leash. I don't want the bench staying there too long if they're underperforming, something Doc has done too much for my tastes during the playoffs... luckily he hasn't done this as much as the playoffs has progressed, evidenced by the shorter rotation.
If he plays well or we're winning handidly, he should get extended minutes, but he shouldn't be getting minutes for the sake of getting minutes with the flawed argument of "he produces if he plays big minutes"; that's simply absurd reasoning.
I really like Leon and all, but I like a championship even more, and if sitting him brings the latter, then I'm all for him not playing. But I want him to do well, but he has to show up during his limited minutes and earn the rest.