Actually if you're moving into a new flat, you should consider designing your WiFi coverage for 5Ghz, and not rely on mesh nodes using
wireless backhual, since you have the luxury of laying ethernet cables for APs before you start with renovation. 5GHz is really the way forward, since 2.4GHz is really congested especially in densely packed apartment buildings like HDBs/Condos.
Think of Wifi as a finite resource and only reserve it for devices that cannot be connected using wires. A typical 4rm flat can be covered with strong 5GHz signal with 2 APs; 1 in the middle bedroom and the other in the living room.
The above is my setup for reference, and I get good throughput pretty much anywhere in my house, less the balcony, bomb shelter and the master bedroom toilet.
The caveat is you need to reduce and tune the transmit power of your APs so your devices doesn't get stuck on the bedroom AP when you're in your living room, and vice versa. The drywall in new BTO flats doesn't block much of the WiFi signal and if you leave the APs transmitting at max power, it's very likely your devices won't roam properly between the 2 APs.