Since @BULLBITCOIN.COM wallet uses submarine swaps (as far as I understand) to send and receive lightning transactions, it should be no problem to install it on two different devices sharing the same seed mnemonic in order to be able to use the same money on either of them. Is that right or is there something I'm missing that would make that not a good idea?

Is it possible to somehow set up @Wallet of Satoshi as a watch only wallet? The idea would be to set it up on a device as a point of sale, from which it was only possible to create invoices and receive payments, but not sending out money for employees to use, while having the same account fully operational on a different device for the employer to use the funds.