The adapter found in the link contains a MediaTek MT7921K which should work just fine for those speeds.

There is another thread on how to disable the built in Wi-Fi and put the UBC 1322 into bridge mode. Unfortunately it seems like you have to call your ISP and get them to do it for you. https://www.reddit.com/r/OPTIMUM/comments/ngmh7f/can_the_ubee_ubc1322_disable_wifi/

I would start there that way you can pass WAN connectivity straight to your Eero.

You probably don’t need it, but it sounds like you want it.