Ath10k-ct-htt-mgt pros and cons from an end user point of view

I've read about the htt-mgt variants of ath10k-ct firmware to know that

The HTT-MGT variants transport management frames over the normal HTT tx path, just like data frames. This saves limitted WMI buffers which can become depleted if lots of management frames become stuck in TX queues due to peer that went away.

In addition, at least for the wave-1 firmware, htt-mgt is required in order for 802.11r (fast roaming) authentication to function properly.

But I don't really understand.

My guess is when devices disappear (e.g. going out of range or turning off an IoT smart device) special packets (what are they for?) they fill up the WMI transmit buffers until a time out happens. ? While these buffers are full waiting to communicate with a missing device no communication of that type can be done, so things like 802.11r do not work. Switching to HTT-MGT puts this WMI management with normal device communication which does not have buffers that fill up to the point of blocking communication, so things continue to work.

Albeit perhaps at a lower throughput as more data is in the regular transmission queue. So the the trade off is maybe worse throughput?

If so why not just always use the htt-mtg versions? These seem preferable since things just work? Anybody that wants to tweak their device for maximum benchmark scores could use the non-htt-mtg version?