Depending on the number of scenes we play, it might make gifts overpowered or underpowered. Now, changing the balance is fine, but other gifts are applied all the time, which makes them more or less desirable. Of course, there isn't anything wrong with changing the balance, too ;).<br/>A typical 4-hour session consists, in my experience, of 5 scenes, +/-1, although that was for Exalted :P. We could just track the scenes and allow the use of a once per session gift once per X scenes, or stick to your idea. I could work with either, although I would vote your variant for a game with a set plot, and adapting the session format in a sandbox game.