i am pretty sure you are right!
But i had no extended experience with EQ as you demonstrated here...
Just an anecdote :
My analog tone control of the Sansui alpha are very good...
It is the top of Sansui design history...
My AKG K340 are a TOP headphone for many reasons...
The electrostatic cell of this hybrid work gradually till 4,000 HERTZ crossover for the dynamic cell...
If i boosted with my tone control the higher frequencies, the violin become celestial honey and any bass head will become High head...
This prove what good analog tone control can do ...
I cannot do that with my digital equalizer which i use also to reach nearer Harman curve (with success though)
But only the tone control give me ecstasy after hours of violins listening on good recording with no fatigue, no tinnitus, or stress... On the contrary like a bass head i want more higher frequencies..
It is also proof how a K340 well driven can reach (deep bass and out of the head sound-stage with natural timbre) i never touch in any of my other 10 headphones which are in the bin trash now...(Save the sextett K240 as secondary tool designed by the same Dr. Gorike as my K340 even if for sure they dont even compare they beat the AKG K701 unnatural timbre )
If i had money i will buy one of the EQ you recommended for sure....
But i am happy as i am right now with my 2 systems anyway...
i just wanted to confirm from my experience what you just said :
No doing cuts with a digital EQ or crappy analog EQ will NEVER get the kind of full saturated, note dense, 3D, harmonically pleasing, “tone is king” kind of result I’m getting.