XR500 and EAX15 smart roaming placement

Clearly there are aspects of the "mesh" technologh I don't understand. I found:

"Other extenders operate under a different name from that of your existing WiFi network, forcing you to manually switch between your original and extended networks. NETGEAR WiFi 6 Mesh Extenders, however, simply extend the range of your existing WiFi, even taking on the same network name you’ve always used. This makes for an effortless, seamless online experience, even as you’re moving through the house."

I've used routers that have done that for over a decade. They're called Apple Airport routers. So I expected something else special about the "new" mesh technology.

These Netgear models use a third "mesh" band (5 GHz), but apparently that is much like the user 5 GHz band. Does that improve overall mesh throughput but not speed? Other than more througput, what value does it add?

From Netgear's web pages, I expected the mesh band to have higher bandwidh and a longer reach than the user band. If so, an extender would deliver the same user bandwidth with added latency from the hop.

But do not observe either of these. The extender cuts the bandwidh in half (as ususall). The extender has no more reach than the end device. If I place the extender half way between the distant end device and the central router, it cuts the bandwidth in half for part of the distance betwen it and the central router. So other than a single namespace, what are it's benefits?

The EAX15's didn't work, so I returned them. Both would drop the wi-fi broadcast and that LED would turn red. This was not distance-related. I thappened at 10' and at 30' and to two units. So I canned them.

I'll KISS and stop using this third mesh band. I'll run CAT-6 from the cable-modem to each router. I assume the Netgear routhers will form a single namespace, but with no loss in bandwidth or lantency, and still with a single namespace. True?

I have an XR500 now. I'm willing to replace it if there are better models at similar prices. Or, if I keep it, what model should I use for the additional two? What would give me the longest reaches? I'm measuring 400 to 500 Mbps now, which exceeds my needs, so wider single-namespace coverage without performance sacrifices is what I'm looking for.

I look forward to explanations that differ from the theories I just gave and suggestong on cost-effective models with long reaches.

Summary:

- What values does the mesh band add compaed to repeating a standard 5 GHz channel?

- Do these units only have 5 GHz and those with 6 GHz deliver enough mesh bandwidth such that the wi-fi bandwidth after repeated is the same as from the central router?

- Am I correct that the EAX15 cuts into the XR500's broadcast area with half-bandwidth and longer latency, given it is close to the edge of the XR500's stong-signal area?

- If I phyically wire three routhers to the cable modem, will they maintain a single namespace with maximum bandwidth and minimum latency?

- Why were the EAX15s dropping their user wi-fi bands while the mesh-band LED remained green?

- What models should I use for my three-router, physically wired, mesh network, without breaking the bank. (I could replace gthe XR500 and sell it on eBay.) The goal is maximum distances, not higher bandwidths or thoughput.

And thanks for the great service in this forum.