But hasn't that question already been answered? Lo VHF channels didn't work earlier but work now. So I would guess the answer is YES.
One doesn't need to know how asprin relives a headache to know it works, does one? You take an asprin, your headache goes away. In this case you get a new software release and you get HD channels you couldn't get before. DUH!
Asprin makes headaches go away and software makes the OTA HD tuner work better. So I'll give the answer from my little mind.
You seem to be missing a critical point that others have tried to explain, but for some reason their explanations are getting lost in the discussion.
The main complaints about the HR20 OTA tuner involve the actual tuner performance, i.e. sensitivity, selectivity, dynamic range and performance in the face of multi-path. The question the OP asked has to be considered in those terms, not whether they screwed up the code and somehow didn't have low-VHF working, or did not have OTA turned on at all. Yes, turning it on is an improvement, yes fixing the missing low-VHF channels is an "improvement" Is this what the OP meant? If so, it was a very poor question, whose answer is meaningless. Of course turning on OTA improves OTA. Of course enabling an entire set of frequencies that were missing "improves" OTA. What a silly question! The real question is now that we have OTA, now that low-VHF has been enabled CAN the HR20 tuner performance be improved ...see my answer below.
There is VERY LITTLE that they can do with the HR20 OTA tuner to affect sensitivity, selectivity, dynamic range and multi-path immunity. Those parameters are pretty much "set" by the choice of the tuner chipset. They might be able to do a little "tweaking" here or there....but no one posting here has a clue as to what tweaking could be done, unless they are an RF engineer familiar with the chipset (and its implementation), or are part of the D* design team.
The question by the OP called for nothing but SPECULATION about D* improving the HR20 OTA tuners. It used the word "CAN" ....no one knows. Those of us familiar with RF design issues have said that the chipset is the dominant factor in how the tuner is going to perform.
I don't know what more to say.
As I said earlier in the thread, the important question is SHOULD it be improved...in other words, is it lacking? The answer to that is an unequivocal YES.
If the OP's original intention was to ask if the hardware limitations of the HR20 OTA tuner chipset precluded improved tuner performance via software tweaks, then the answer is probably only a very little, and NO ONE KNOWS FOR SURE, without the technical competence to address the question.
The fact is, as consumers, we don't need to know the answer to that question. If the tuner's performance doesn't meet our needs, we need to hold D*'s feet to the fire to improve it, however they can. They may reply..."this is all it can do", and in that case, the answer to the initial question is NO.