I'm no RMAN expert, only been using it a few months, but my understanding is this:

If you do a level 0 once a week, and a level 1 the rest of time, the level 1 and any level 0s that are needed will be restored. On the otherhand, if you do one level 0 once a week and level 1 cumulatives all the others days, when you recover you only need ever use the most recent level 1 and the most recent level 1 cumulative (for complete recovery, of course). Perhaps you could consider using the cumulatives. Hope this helps. Austin