So I've been working (very) slowly on this section for the past few weeks.
https://coinb.in/#settingsThe idea is to make it easier to retrieve your inputs for a transaction and broadcast a transaction via coinb.in or a number of other third parties, as well as making it easier to use bitcoin testnet (and eventually altcoins).
At the time of posting this, I have only added multiple hosts to broadcasts too, and have not yet added any services to retrieve your inputs for a transaction.
Once complete though this should make coinb.in even more resilient and decentralized than most wallets.
Feedback and suggestions are welcome.
So, as far as I know, there are no wallets/services that allow for Trezor+multsig (well, there's Greenaddress, but that uses their servers to do stuff).
Any chance Coinbin could be the first to do this?