Android allows fuller nostr user experience. On Android Minibits lets you send and receive zaps from just minibits, also pay LN invoices. No second lightning wallet needed.

Yes on ios there is a sending zap issue but not a receiving zap issue with cashu. There are other sending zap issues on ios not cashu specific as well. ios users can dm sats with cashu. No second wallet needed.

Cashu wallets can pay LN invoices.

New users have to use a custodian LN wallet to start from 0-100k sats anyway so no different single custodial risk.

User's have to have over 100k sats for a self custodial LN channel no matter what.

That is when a second self custodial LN wallet comes into play.