BT Mini Whole Home Wi-Fi - need to disable existing Wifi?

Hi all,
Apologies if this has already been asked and answered but a quick search did not provide a definitive answer...

I currently have a Billion BiPAC 8900AX R2 and planning to get a BT Mini Whole Home Wi-Fi setup to improve Wifi coverage in the house.
What I cant seem to figure out is if I will need to disable the Wifi on my Bipac or can I continue to use that as well as the BT discs?
I ask because I already have an ethernet cable (+ dumb switch) at the back of the house - so I figured the Bipac Wifi signal can continue to service the front of the house and I can wire the disc at the back of the house + upstairs etc.
Otherwise, I will have to buy + power an additional disc at the front as well. And my wife would not be keen on another disc at the front as the wiring etc for the BIPAC is well hidden etc and another device would make a mess.

You need to read the manual for the discs but it is quite possible that if you have two of them connected devices such as laptops and mobile phones can automatically move to which ever disc is providing the stronger signal. This may be a benefit to you. I suspect that if you have the BiPAC and a disk this won't happen even if both are using the same SSID and password. But again you would need to read the BiPAC manual to find out which switching protocols it supports.

I just use two old routers for Wifi so I don't have auto switching, but I only have a few wifi devices and they don't get moved about very much.

i have a billion 8800nl you will need to disable wireless bridge restriction on the router