Bidirectional communication would entail switching to receive mode after sending METERING2 for a certain amount of time & switching back to transmitting.  The receiver would switch to transmit mode a certain time after METERING2 & resend its status a few times.  There can't be any detection of packets during the reversed mode since there aren't enough clockcycles.

METERING1 typically comes 90ms after METERING2.  MANUAL FLASH has been seen 14ms after METERING2.  PREFLASH1 has been seen 15ms after METERING2.  The time measurements are from the 1st byte of the previous packet to the 1st byte of the next packet.

A certain amount of time is required to capture, transmit & replay METERING2 on the flash.  After METERING2, it would spend 5ms switching radio modes. 5ms would go to a window for receiving the status.  Another 5ms would go to switching radio modes again.  For 15 ms after METERING2, it couldn't receive any packets.  There's a good chance of it missing a FLASH packet.

There's always the chance a METERING2 is never sent before the exposure but chances are high that at least 1 flash state would make it to the camera.  It most certainly requires 2 radios to be reliable.

An easier but less capable solution is to simulate the mode on the flash.  Exposure compensation just adds a fixed offset to the power & shows a setting in the viewfinder.  All multi does is send MANUAL FLASH instead of MANE FLASH1.  Manual mode would eliminate the preflash delay but no lion has ever used an off camera flash in manual mode, let alone desiring lower latency.  2nd curtain sync just reverses the trigger signals.

The trick is the flash times out after waiting for a trigger for 1 second, to avoid crashing.  2nd curtain sync & multi would entail waiting for codes without having any timeout.  These modes have never been used by lion & they could be implemented later if the need arose.

Of course, there's always the desire for the most complete solution possible, just for shits & giggles, but we have to move on to the user interface, enclosure.  The biggest loss might be the icons in the viewfinder for the flash mode.  It's basically halfway between a Neewer which does nothing & the Godox which does everything.  It's just enough.

It's impressive that Godox employees in China implemented enough of the ETTL protocol to support all modes on all flashes, but they paid for a license, had full documentation, & had unlimited money.  They might have 2 radios for 2 way communication but lions have never seen that in a consumer product.