TP-Link AX72 Pro or Deco X60 AX5400?

I currently live in a 1500 sqft 3BHK apartment, but will shortly be moving to a detached house with two floors, with the possibility of expanding to three.

My current situation is this:

At the apartment, I have a 1Gbps FTTH connection over a 5/2.4 dual band modem, which I have shared to the other two bedrooms (one bedroom, where the Wi-Fi modem is located, is being used as a computer room) via Gigabit switch and EAP-115 AP's, and to the living area via an RE850 extender.

Now, I would like to enhance this network to Wi-Fi 6, as all our phones and laptops/PC's support that standard.

To do this, I plan to buy one of the above devices, with the intention of carrying it over to the house I will be moving to (around 4000 sqft across two floors), and expanding if needed by adding either an AP or another Deco node as the case may be. Backhaul will be through ethernet.

Which of the above devices fits my scenario best?

Will it be possible to disable the GPON's wireless entirely and depend only on the routers/mesh device(s) for Wi-Fi?

If I install either of these devices on my existing home network, will they interfere with the EAP's/extender?

Am I right in my understanding that the Deco devices will form one single network to cover the whole area while each of the routers will form its own sub-network?

Thanks in advance for all the help and advice.