Depends, you can externalize that and use a third party mint. There are some money transmission laws about keeping a custodial balance? I would say it's the same. Instead if you run you custom denomination mint these tokens are not money itself, just utility tokens
Discussion
There are laws around allowing withdrawals. If a service allows withdrawals, then they generally are considered a wallet and have to respect MSB laws.
But yea if you just have them as non-withdrawable credits then it might work. But at that point why not just do a simple top up?
The one advantage I'm aware of is the blinded custodian thing so thats +1 for ecash tokens.
You can run a mint for yourself for only your application with exactly your requirements (limit withdrawals etc)! Hit me up if you need any information, happy to help.
