Hi,
I have a B.A.T.M.A.N. Mesh running which runs fine but my WiFi maxes on around 70Mbit/s where my wired connection goes max of it's speed.
I think there is an issue in my WiFi config as the base config did full speed on my 200Mbit/s connection before over WiFi.
I test this at the moment on my main router with my Mesh nodes turned off; so there is nothing in between. When I wire my PC to the main (Mesh)router I get full 200Mbit/s
Sure I checked most things that are standard known for OpenWRT performance; which things are still able to check for me ?
I would first split this into Wi-Fi and mesh/B.A.T.M.A.N. parts. With the mesh nodes off, run a LAN test like iperf3 between a wired client and the Wi-Fi client; WAN speed tests add too many variables.
If LAN Wi-Fi is also stuck around 70 Mbit/s, post the wireless part of /etc/config/wireless plus channel width/band, encryption mode and the client link rate from iw dev wlan0 station dump (use the actual radio iface). Also check that the AP did not fall back to 20 MHz, legacy rates, or a crowded/DFS channel. If LAN Wi-Fi is fast but only WAN is slow, then I would look at routing/firewall/SQM/offloading instead.
I think you didn't read what I already tested out; it seems at this time with 2.4Ghz you must be happy with 70Mbit/s; 5Ghz goes far over it (of course) but I turned that off for tests it seems.
40Mhz is used; but some people even advise 20Mhz because of crowding.