Firstly, it is better not to address the question directly to me.
I am not a networking professional and my opinion may be wrong or biased. I do not reply to technical questions using pm because of this reason since others cannot correct me or offer alternative suggestions. And when you address the questions to me, other people may not want to reply already.
My comments below are for your reference, just my personal opinion. Standard disclaim applies:
no warranty, YMMV. Free suggestions, no charges either.
1. Internet plan --> M1 6Gbps with a pair of Asus ZenWiFi BT10 should be good to go.
In terms of cost, both M1 6Gbps plan or Starhub 5Gbps plan, the difference is not big.
M1 6Gbps with a pair of Asus ZenWiFi BT10 --> S$59.90 per month
Starhub 5Gbps ONT offer with EB810 (S$360) +EB810v (S$360) --> effective price at S$29.55+S$15 x 2 = S$59.55 per month
Starhub 5Gbps ONT offer with EB810 (S$360) +HB710 (S$192) --> effective price at S$29.55+S$15+S$8 = S$52.55 per month
Since you are using M1, I think recontract with M1 is easier. M1 may have better customer service than Starhub and M1 digital voice is free.
2. Wireless solution -- better to lay Ethernet Cable to the rooms and use Ethernet Backhaul
The floor plan is again a difficult floor plan due to the location of the household shelter location. Recently in the forum I have seen similar floor plans a few times, some are BTOs with LAN ports in the rooms, some of resale plats without LAN ports in the rooms.
I do not think your original plan will work well using wireless backhaul. The mesh node in the Main Bedroom cannot have good connection with the main node. Areas like the kitchen and service yard may be poor.
So it is good to pull Ethernet cables to the rooms, including one LAN port in the kitchen area. In that case, you can use the following configuration. The patch panel can be in the existing LAN port location in the living room.
M1 XGS-PON ONT --> Asus ZenWiFi BT10 unit 1 as main AImesh router in living room (10G WAN port)
ZenWiFi BT10 10G LAN port --> patch panel --> LAN port in Main Bedroom (can also be the centre bedroom) --> Asus ZenWiFi BT10 unit 2 as AImesh mesh node (Ethernet backhaul)
ZenWiFi BT10 1G LAN port --> cheap 1G switch --> patch panel --> LAN port in the other two bedrooms and kitchen area
LAN port in kitchen area --> cheap AP if WiFi is poor, for example, RT-AX3000P in AP mode (probably not a good idea using AImesh in this case as it is a low end WiFi 6 router and not a good match with ZenWiFi BT10).
It is also possible to upgrade the above configuration easily in the future. For example, you can add a 2.5G/10G combo switch after the main ZenWiFi BT10 10G LAN port and then distribute the 10G port and 2.5G ports to the other rooms, or even a pure 10G switch when the price goes down.
3. Second option -- die die do not want to lay Ethernet cables --> not recommended
Get one more node of Asus ZenWiFi BT10, probably at about S$400 to S$450 if M1 users start to dump the router.
M1 XGS-PON ONT --> Asus ZenWiFi BT10 unit 1 as main AImesh router in living room --wireless backhaul --> ZenWiFi BT10 unit 2 as AImesh mesh node in the right bedroom --> wireless backhaul --> ZenWiFi BT10 unit 2 as another AImesh mesh node in the main bedroom
You may need to optimize the placement to get the better results.
Kitchen and service yard area may still have poor WiFi unless you add another BT10 in the lower side of the living room (line of sight with main router in the living room).
