You have to install the trezor back-end full node as well and have that connect to the Bitcoin Core full node ... so need to run two full nodes to support one wallet locally ...ok, nah.
You only need blockbook which apparently uses and maintains its own instance of Bitcoin Core, so you don't need to run two full nodes. I asked on their Telegram channel if it was possible to connect an exiting Bitcoin Core instance to blockbook and I got "Yes" without any more details.
This config file might be worth taking a look at.
Ok. Still it looks like an arcane set-up.
How is it after all this time the top bitcoin client fullnode, Core, and the top h/ware wallet, Trezor, are not seamlessly integrated?
Long past time they need to get past their little bitch fight that started back when and do the right thing for the community.