Does this mean that you cannot check the balance of an address with Bitcoin Core and that the utility of connecting the hardware wallet to Bitcoin Core is to use that node to issue new transactions?
What i mean you cannot check blance of
any balance quickly due to lack of index. But you still can do that by creating wallet which contain specific Bitcoin address or master public key. If you add one which already has past transaction, Bitcoin Core will need to rescan blockchain which could take some time.