If Levi is clearly the best goalie on the roster, play him. Not ifs or buts. If he's in contention for best goalie and clearly the second best goalie on the team, roster him. This team is no longer about potential, time to produce wins and playoff runs. Play your best players.
The issue is conventional wisdom is against him. The safe thing to do is to protect him the last few games here, and send him to Rochester next year. No one will doubt that strategy.
The concern is playing him short term this year as a starter and whether that would do any damage to his development, the team confience in him, or their playoff chances. If you believe it will, then you don't play him. If you believe it wont, then you play him in that starter role.
The x factor to all of this is what is motivating the Sabres if they play him this year like a number 1 and who's best interested they have in mind.
Granato and Adams are in a tough spot, but also, this is a 'good problems to have' discussion. Big picture, this team is on the precipice to big things.