Mycelium has what is called "Cold Storage Spending" last time i scanned a QR code from a paper wallet and i do this a lot, it comes up asking how much to transfer. I just always select "max" and hit send.
I have often wondered what would happen if i didn't send all the funds having no change address but never wanted to try it.
I kinda gathered it would send change back to the paper wallet addy but I want to clean it out. once that paper wallets private key has been used its useless to me for storage anymore.
I have tested some of my BIP38 paper wallets before but this will be a 1st on my phone.