Thinking outside the box
I agree with everything you've said, but there is this to consider; There are already thousands of L-A and Magnum 360s in swapped-in "hot rods" such as my Valiant, Dusters, Darts, Demons, etc. The "3rd-generation Hemi" is new enough that the number of them running around in Dusters, etc. as street/strip cars is relatively small, right now.... but, of course, that will change as the junk yard supply for these motors continues to increase, over the next few years.
The odds are that most of the Hemis from junkyards are going to go into new projects; I can't see guys who have already invested in a cam, headers, heads and a good intake system/carb setup for their 360, yanking it all out and replacing it with a "new" Hemi just because they can. What do they do with the old motor? They could sell it, but a motor like that is not going to pay the seller anything like what he's put into it, usually.
It's people like that, (myself included) who already have a lot invested in a360 wedge motor that need these reasonably-priced 300cfm heads, and I think the market is there for them.
Like you, I attacked the problem with forced-induction, but as you have found out, probably, there are no simple solutions to making a 360 Magnum breathe (without spending a small fortune on W9 heads and all the attendant hardware.)
But, supercharging is not cheap, either, if done right (forged everything, a 6-bolt-per-cylinder block, and a mega fuel system, boost retard and a $500.00 water/alky injection system.)
Supercharging isn't for everyone...
So, we're back to the guy with the EXISTING "hot rodded" Duster who doesn't want the hassles of swapping in a 440, to replace his 390hp crate motor 360, or necessarily, to drag out that $5,000.00 wedge he's got his money invested in, to put a junkyard Hemi in, ALTHOUGH it really IS the wave of the future.
Better heads if relatively CHEAP ones can be found, would be his best option, but as you have pointed out MA ain't gonna be providing them.. That's why I thought EQ would be the better candidate, since they obviously have the engineering wherewithall to build cast iron heads at reasonable prices.
But, it will never happen... and you have done an excellent job of pointing out why it won't. Sometimes I need to be jolted back to reality... lol!
Thanks for the considerable insight.
Bill