Is Eero an option?
Will an eero solve my issues?
I seem to have reached the device limit on my existing ISP supplied router (Uk TalkTalk FAST5364 3.00 with FTTC with 70Mbps download (15Mbps upload)) with just under 50 devices now active. Symptoms are that devices become unable to connect and some being slow to respond. Speed of connected devices seems fine.
I spoke with my ISP help desk and suggested I try an Eero but they said an eero would not work with my FTTC router. Is this correct?
My assumption was the eero manages the IP assignment and I would turn off the wifi and possibly the DHCP server elements of the ISP supplied router so it becomes a "dumb" connection to the internet?
As an aside - It's a big house and to solve some early range issues some devices are connected via ethernet lead (via a switch) and I have a second wifi access point in the loft (also connected to the router via ethernet leads). Nevertheless over time the number of devices has steadily grown to around 50 and I now have issues.
Yes, eero should work fine for you. With the default subnet that eero uses there is room for over 1000 devices to connect. eero also has the Optimize for Conferencing and Gaming option which should allow it to more fairly distribute the speed you have available (devices may not connect as fast as they can with this option enabled but no one device can monopolize the available bandwidth) to your many devices.
You can try the eero both bridged (with your TalkTalk router being in charge of the network) or with the eero router running (you don't NEED to disable the TalkTalk routing to do so, you can run a doubleNat configuration (where you have internet->router for network A->router for network B->Devices, in this example the TalkTalk would be router A and the eero Router B)).
I know that TalkTalk does supply some of their customers with eero, try contacting them if you wish. If you want to get your own make sure to purchase via Amazon or another place that has an easy return period just in case they don't work out (although I'm sure we can get it going satisfactory for you, make sure you talk to us if you have any issues).