I don’t think that will be a good indicator as I run many apps on the router itself. Stream 4k content over wifi to tv (5ghz band), download torrents using router itself (to usb3 disk attached)… etc

I think the ipq40xx is one of the best platforms for openwrt at the moment, ipq80xx is crippled because NSS cores are not in use.

ipq40xx has 4 normal arm cores for all tasks so its fully utilized. You might want to consider mt7621 since it has hardware acceleration and could get line speed, but running other tasks like the ones I mentioned, the quad ARM cores are more potent.