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Your NMTS key now opens as many wallets as you want, each under its own number, and Settings › Wallet and payment lists them with the one that pays.
The numbers come from the key itself, so the same wallets appear on every device and none can be deleted. One wallet pays at a time; switching is one tap and needs no confirmation. Find wallets with funds scans the numbers in order and stops after twenty empty ones in a row, the way hardware wallets do. The command-line tool has wallet list, wallet use and --index, and the SDK has wallets() and setActiveWallet().