Unesco, your post brings the following to mind:
“The question is if you really want to have maximum neutrality?”
I’m still trying to develop a useful qualitative understanding of “maximum” neutrality (to use your term) and whether it really is visually superior (i.e. as a practical/aesthetic matter) to a neutrality that is instrumentally “off” but not eye-perceptibly “off”. Are there no circumstances where a BW print would look neutral even though instruments would say it isn't "maximally" or perfectly neutral? While I am seriously curious about these things, I’m unable to undertake the meticulous work I think would be required to get an answer to this. I depend for now on threads here and readings elsewhere.
“Have you tried warm/cool prints (still monochrome) or duo/tri tones?”
No, these are areas of BW printing in which I have not been interested, except for some casual trials when I first got my printer.
“It should be remembered that paper white tint have influence on final neutrality.”
Aside from a paper’s overall (and often desirable) aesthetic effect from it’s tone (e.g. a warm baryta vs. a paper that is cold from OBAs), I am curious whether you are referring to an effect I am familiar with from oil painting where, if you have an oil-rich glaze or a light scumble over a toned ground, the ground will show through and contribute to the perceived tone, but a thick opaque paint layer of whatever tone will hide the toned ground. Is this analogous to what you are referring to? Is there a “maximum” neutrality achievable in a BW print by developing a profile that would take the translucency/thickness of the deposited ink into account in order to “counter” the increasing effect of the paper’s tone as less and less ink is applied in the light tones?
In my way of thinking about it, any effect of the paper's tone is a given, and the question is only whether the ink that is printed is neutral (visually or perfectly) across the full range of tones.