You can sign and verify messages with Trezor hardware wallet using their web wallet wallet.trezor.io and same functionality is in the roadmap for Trezor Suite software, planned for September 8th.
He was probably referring to PGP signed messages and not Bitcoin signed messages.
I shall see if I can move onto Linux in the future.
You don't have to move at all; that's what WSL is for. After following my instructions, launch Ubuntu through WSL (you should be able to launch it easily by typing in "Ubuntu" in the search bar), create a new key pair using Trezor's instructions, type in explorer.exe . and put the files you want to sign/encrypt or verify/decrypt in the new explorer window, follow Trezor's instruction again and you should be able to copy the output files from the same explorer window.
