Might this be relevant.
@greearb: ath10k-ct firmware plus driver reports proper tx-status for every frame transmitted (and rx-status for received frames0. This means the mac80211 stack can calculate the airtime used (close enough at least) and thus can make decisions at queueing level to enforce ATF. I do not know if stack currently can do this or not, but I suspect it can since ath9k and older mtk radios would need and use similar support. Please see if that can somehow be enabled for ath10k-ct.
My apologies as a "non-expert" it takes more effort for me to comprehend.
EDIT I interpreted @greearb response as "it's possible" for my device. If I do "enable" ATF for my device, an initial test here (netperf AP-> 2 clients) seems like it might be working.
Last EDIT: i'm ok with the response "possible yes, likely to be supported no" but I would very much appreciate just one more response. I'll put this "to bed" if the response is "not likely to be supported." Thank you again for taking the time to respond.