I would keep everything as wave or broadcast wave files when moving to another app. Mp3 is not the best format for this activity.

Yes, that occurred to me. The other app is running on an iPad and I'm afraid of running out of memory.
 
When you say "not the best format", are you referring to audio quality? 

There could be sync problems too. AFAIK, no DAW natively uses a lossy compressed format like mp3. They all use an uncompressed format and convert files in other formats on import.

Ah, ok. Well the iPad app is just a playback app, no editing or other DAW-like functionality involved. The driving factor is memory space right now so if the mp3's work out in terms of quality and sync I think it would be the best choice in this case.
 
We shall see! Thanks for the insight.