I am not claiming I am an expert, this is just my opinion:
I heard about modulating the rail according to the input signal so you have low voltage across the output stage all the time. I think it was Sun Fire or something. It is not for free, because of the early voltage of the output transistor, changing the collector voltage changing the characteristic of the transistor and creates distortion. So it is not free lunch. I don't know how much it will affect the sound, but it is NOT simple class AB by any stretch and I do not believe you can get the performance of a true class AB.
There are many attempts to keep the amp in class A region using variable bias, many patents had be written including one by Nelson Pass in the 70s, I simulate a lot of them, none of them work, they create more distortion than people expect. that's the reason they never get into the main stream. When you talk about higher end amp, everything matters. As a guitar amp designer before and currently designing a hifi power amp, you never use equipment for different purpose.
As I said before, since OP has the amp, try it, talk is cheap. If he like it, keep it. But if not, and if he can sell it for $1500, you can get into a used class A amp that is going to be in a different league.
Lastly, why do you want 2000W for hifi equipment? You hardly go beyond 5 or 10W with transient seldom reach 100W. You waste power, operating the amp away from optimal region. I just get the feeling some people think more is good, much more is better. I don't think that's how it works. You have the sweetest amp that is single ended tube amp that are under 10W.
I don't claim to be expert, but I do have a large collection of schematics of high end hifi amps, never seen one with funny scheme, that says a lot what the true experts think.
From my experience, there is an optimal loudness, if you crank below that, the system( amp included) does not open up, too loud, it get distorted. You try to keep the system operating in the optimal......that is to know what is your listening level and buy accordingly. You get a 2000W amp, you never run it in optimal level.
I am designing my first amp, but I have been EE for a long time and designed guitar amps before. I did a lot of study and I end up designing an amp that is only 60W into 8ohm and 120W into 4 ohm. I am more concentrating on having the amp running in clase A for the first 16W with 8ohm or 8W in 4ohm load, that's where my sweet spot. You got for bigger the better, there will be a lot of sacrifice in the design, believe me, I know that, been pulling hair for a while.