What I need is a router that will be my new router and "co-operate" with the AExtreme in beam forming, so that the handoff to my MacBook Pro 2019, my iPhone Xr, my wife's iPad and iPhone Xr, my Home Pod is seamless
Seamless handoff was not built into the Airport series at any time.
Extend wireless (proprietary version of WDS) which apple used throughout their 10year router gambit, is renowned for holding onto all those iOS gadgets you have and not allowing them to switch.
It is important to note that really truly seamless handoff is still a dream.. somewhere over the rainbow.
And mixing brands makes it near impossible to work. Although there are several new standards that should enable this to work across brands, the reality is even the best available can be frustrating and difficult. Much of the problem is the client configuration which is not accessible in iOS to any extent.
Very few test reviews include handoff. So you tend to get lots of static location setting of how good the wireless speeds are; almost nothing about how well a particular setup works with mobile phone brand xyz.
It is unlikely to happen soon either as that level of real world testing is really difficult and what works in one place will not work in another. Small differences in phone age, iOS versions, how you hold it even, would make consistency impossible.
100% with Bob on mesh. If your principle criteria is handoff then Netgear Orbi. It works great with ethernet backhaul too. You can buy the bit cheaper RBK40 set as the RBK50 includes a much faster wireless backhaul which you will not use anyway. Check pricing as the difference is seldom as great as it should be due to volume of sales of the better kit.
With a wired setup you can also look at Ubiquiti which also has sophisticated roaming built into their AP series. The learning curve is steep but the products are not over expensive and well made.
TP-Link make equivalent series called omada. It is a bit cheaper and works just as well. Not very well known.
It will never have the level of support that Ubiquiti offers. I like the omada series because the AP have built in setup. You can configure them like normal router via a browser. The full power of it is only when you use it with the controller though.
Don't mix brands.. that will not work. Mesh always requires single brand. Even with IEEE standards the amount of tweaking that goes into making this work with even a semblance of the old Apple standard.. It Just Works.. is impossible.
Will i be able to configure my new main router (by web page, I know) so that settings are the same as the AEX's?
The issue with most domestic mesh systems is they actually are designed rather too simply and require use of company cloud login and phone app. Orbi does stand out as having a web setup although the phone app approach is also supported.
I don't like signing into a company just to configure a router over internet. So I will never buy products with that limitation.
Don't bother replicating the old AEX .. you will do much better starting from scratch.
