To your ISP it would look like encrypted websocket traffic but is easy to detect what it is if they wanted to.

I don't recommend Tor for things like this unless you have an extreme threat model as it would drastically affect usability for you. A VPN is a much better set of tradeoffs for most people, but I do definitely want to see Tor as a broader option for relays and clients!

It's something that should always be optional but isn't usually recommended.