I actually do have a US brokerage account with Schwab so I have just contacted them and asked if I'm allowed to receive 3rd party wires and the answer was yes.I haven't received any 3rd party wires up to now, so I don't know, but I don't see why I couldn't.
I don't think Interactive Brokers gives you a checking account, just a brokerage account, maybe that is why they don't accept 3rd party wires.
But any U.S. bank will allow you to receive 3rd party wires.
I would contact Fidelity and Schwab and I'd ask them, both Brokers will give you a checking account, as well as a Brokerage account. I don't see why you couldn't receive 3rd party wires into any of those checking accounts, but check with them to be sure.
That's a good start. International outgoing wire fee (to eventually withdraw the funds) is $15, it remains to be seen if my EU bank will charge me for the incoming USD wire (sometimes they do sometimes they don't). It's still a better solution than asking US payers to use Wise to convert their funds and send Euros
Will update here once I've gone through the full process.
Thanks!