Good day.

Please refer to the following information:

1. Will my units receive the update and be capable of this functionality?

--Currently WPA8630P V2 does not have a plan for OneMesh. You might need to keep attention to our official website for updated news. And it would be much recommended to buy the extenders which are already OneMesh compatible.

2. Presumably, my router must also be TP-link and mesh capable?

--Yes, the main router needs to be TP-Link OneMesh compatible as well;

3. Is there a particular router you recommend? Note my internet speeds are limited to about 30mbps.

--Archer A7 would be fine.

@markstillwell  Hello, 

Thank you for being interested in tp-link oneMesh feature. Currently we did not hear a plan for WPA8630P V2 oneMesh feature. 
For the latest news about oneMesh, please always refer to One mesh Compatibility List on the TP-Link official website :
https://www.tp-link.com/onemesh/compatibility/

We would record your suggestion and forward it to team for further evaluation. 

Kindly note that " Planned" is not a guarantee for oneMesh feature, and the Planned models might be updated and modified as the notice on the top compatibility list. As a presale suggestion, please consider the models that already support this feature.  
Your understanding is much appreciated.