For TP-Link Support,
Why Archer C7 V4 don't receive new firmware with OneMesh and V5 with basically same hardware does.
It's bad because don't make any sense buy another router to have this feature.
Below is the onemesh compatibility list. https://www.tp-link.com/onemesh/compatibility
Per you know, there will be a firmware for Archer C7 V5 to support onemesh feature.
Besides, the onemesh feature applies to the latest hardware version of the C7 at first, that is why there is no plan to support it on C7 V4 yet.
While you can keep an eye on our official website for more details, any updates, we will post there.
May it help and have a nice day.
You are very welcome; do not hesitate to contact if you need any further help in the future.