While you are absolutely correct that would save packets and time, there are way too many packets lost in HF radio for something like that, unfortunately. It is not uncommon to miss over other, every third packet. Even the small ones. Something like ardop or Vara does their own acks and systems for error correction, which work fine. But there is zero chance you can proceed with our them and still keep the connection going. I'm fact, on HF, sudden complete signal drop is common.

I'm also in no way going to redo the packet stack at this point, lol.