No:
if (hapd->conf->skip_inactivity_poll)
sta->timeout_next = STA_DISASSOC;
When skip_inactivity_poll is 1 (checkbox ticked in LuCI) the code block below the above will be skipped and it will run hostapd_drv_sta_disassoc() a few lines further. It will not do any polling and directly disassociate.
It is in the first post, check my option max_inactivity, it is way higher than what is happening in the logs and I already explained why this is unrelated to inactivity polling.
Already tried that, no changes in behavior.