I think we will need som decent jurisdictions where one of the following happens:
1. Ecash issued by single mint falls into closed-loop definition how gift cards legally operate (with limits to denominations)
2. Ecash issued by private banks will get green light after CBDC with some similar traits fails to get user traction

Other option is to discover some clever and complex trick where mints would issue ecash based on some special funding transaction with timelock, w/o having complete custody over funds but able to provide denomination/intermint swaps for a fee. May be this could be constructed with some statechains primitives, where mint would stay in role of coordinator and thus more resistant to regulator attack. Not sure if doable with low onchain footprint.