Obviously you can create multiple wallet addresses with one Trezor hardware wallet and just one seed phrase. However, I don't know if one seed phrase has more than one BTC address,
what I can be certain of this, that one seed phrase can create a million or a trillion bitcoin address on Trezor wallet.
if our Trezor hardware wallet has problems such as a dead screen or other problems, other BTC wallet addresses (not the main wallet in Trezor) can be accessed in other BIP39 wallets or not.
during the wallet support BIP39 mnemonic seed, you can access your bitcon using it.
My advice is that if you want to create other addresses on a single hardware wallet, make sure to also create a phrase for each wallet address. This is done in anticipation as a backup so that the funds we store there can be accessed safely and well in all conditions.
This way is not done to anticipate in what you are afraid, because almost bitcoin wallet out there is Hierarchical Deterministic (HD) wallet where you create multiple address with 1 seed phrase.
And, believe me, the way you suggestion above will make you confused itself if each address you create uses disparate seed when have problem to recovery it.