All the tutorials seem to suggest that one must add the contract address to tokens for Tether. I inadvertently sent a test to the Eth address without doing that, but Trezor automatically created the Tether token. Is that okay or is there some disadvantage to NOT adding the token contract address manually before receiving the token?
there is no need to add the contract manually. After you send ERC20 token to the ETH address that you can find under your ETH account, you will see the token under the “Tokens” tab automatically.
You can find more information on how to use ERC20 tokens in Trezor Suite in the video linked in this thread: How to use ERC20 tokens in Trezor Suite - #3