The whole point of buying the Terzor was to get away from a bunch of other wallets. They said it's supported, and yet it's not supported except through other wallet? That's crap.
That is the case for many other coins, and you can't expect to have one universal wallet for all coins and expect everything to always work.
You are still keeping
keys offline, that is the main point of hardware wallets, and it can be even better to use familiar default Electrum wallet as interface.