So I have discovered that my old Archer C7 is reaching a throughput issue with all my devices connected (40+).  As a result, I'm looking to upgrade my router to something more like the Archer AX11000 v1 which is 'planned' to support OneMesh down the road.

I already have two RE300's in onemesh mode hooked to my C7 extending the range effectively to the limits of my home and detached garage. 

Here's my question:   If I went ahead and bought the AX11000 and waited for the possible onemesh firmware to come out, in the mean time would I be able to put the Archer C7 on an ethernet cable attached to the AX11000 with the C7 operating as an access point while still having onemesh RE300s hooked to the C7 for a single SSID?

Effectively this is what I'd like to do, if it is possible:

Modem->  AX11000 with wifi disabled -> Ethernet cord to C7 in Access Point Mode -> Wireless bridge with onemesh enabled to RE300s for extended range.