I'm not sure exactly which post you are referring too, but I find the layout presented here to be interesting. Although I personally believe the H-20 is a subsonic flying wing.
A longer supersonic layout also presents the possibility for a longer weapons bay. Something often attributed to the cranked kite design in CG's of the H-20. However compared to the B-21's design with a uniform leading edge, studies have shown those sorts of wings are less stealthy. This is why I believe the H-20 is likely similar in shape to the B-21 and not exotic like shown below, or have folding stabilizers like in fan CG's.
Frustratingly, i haven't managed to find the post in question so far (maybe it wasn't on SDF but somewhere else?), hopefully someone must have seen it? The drawing in question reminded me of the B-2 from the front, probably because of the dorsal intakes.
I am aware that most PLAAF watchers believe H-20 to be subsonic but recent rumours of a supersonic H-20 are tantalizing to say the least. Would China be best served by merely mirroring what the US is doing ( ie subsonic H-20), or be bolder and more innovative to gain an advantage (supersonic H-20)?
On the question of range, does it really mater that much for China's strategy if a supersonic H-20 would have shorter range, it's not like they'd want to send it over San Diego to drop free fall bombs right? If they really want to attack the US mainland targets they could still use hypersonics and ALBMs including from the H-20. A combat radius reaching Hawaii would probably be enough, maximizing the aircraft's capability both standalone and within PLAAF's ecosystem to thwart and blunt any potential US aggression in the Western Pacific area, ie effectively countering and destroying US aircraft and naval forces attempting any operations within this area.
