What IO would do is configure the AX10 as an AP and assign the same SSID and password as the EE hub. Place it in the room where your WIFI is week and connect it to the Ethernet port there. If you need more coverage, purchase another AX10 and repeat the same steps. Putting the router into AP mode is easy and you can find the directions here:

https://www.tp-link.com/us/user-guides/archer-ax10&ax1500_v1/chapter-4-set-up-internet-connection#ug-sub-title-4

https://www.gocoax.com/

Do you think they will mandate a switch over to Frontier only, or will the residents have the choice between Spectrum cable and Frontier WiFi/fiber?

That will be decided by the apartment management. You should ask if you are able to use another ISP, but it will probably be out of pocket.

If you work from home and need secure internet, Frontier bulk is not for you. My sister in law lives in an apartment complex with shared internet. When i did a scan of her network, I could see other people’s devices on the network.

You would need a switch like this to do both passive and PoE/PoE+.

If you place the Virgin hub into modem mode, then you will need to reset the Deco system and set them up as a standard mesh system. Not as APs

If you changed the Virgin hub to modem mode, you need to now reset your Decos and set them up as standard mesh instead of APs