Good evening,
I have a small concern and would be happy if you could help me with it.

I would like to set up a cold wallet on a computer without internet access (Electrum) and a pure watch wallet on a computer where the fullnode is running.
Then I wanted to create the transaction in the watch-only, then move the transaction file to the airgap computer and sign it there.

Question 1)
Do the hardware wallets for the MultiSig function all have to support PSBT?
Or can I also use Trezor / BitBox, for example?

Question 2)
If it were also possible with Trezor / Bitbox, where do I sign?
On the watch-only or on the air gap?
I think you would need internet access for Trezor & Bitbox, or is it possible without internet access on the Airgap computer since the hardware wallets are linked to Electrum there?


Thank you and best regards