Dual volume control - it should be standard

Yep. Redgum can provide the belt for $15 that will do just that. No need for me.

They certainly make the presentation of space more correct.
I don't often use them for each individual cut unless something is very wrong but always do for each recording. And, yes, especially for analog recordings or those digital transfers that tried to preserve as much of the original recording as possible including noise and unbalanced channels.

We have ears to match levels. Preamp with single control and power amp with dual gain controls should be fine too, right? Is it the same or not as having dual volume controls on the preamp? The result, I mean.

It took me about a week to get used to. No obsessing. By the way, in many recordings right channel is louder to various degree.

If someone says yes, there will always be those who will say no or it depends. However, it appears that people who are not too lazy and have good hearing say yes in this case. By the way, Redgum has now an option of single volume control, but they warn on their website that it will sound a little worse.
Also, moving the listening position left or right will not always help and can actually cause even more soundstage distortion. Depends on room and recording, I experimented with the amp I had before with single control.
The point is that there is no way around. At least none that I can see.

Committed is an understatement. Totally dedicated and profoundly submissive.