Generally a good idea; and, some caveats:

here on LW

Let's remember that there is no "here", here. This is a virtual forum, and text is too low-bandwidth to form an opinion of a person qua person.

As a case in point, you specifically, i.e. Vladimir-you, as opposed to cousin_it you, made an almost entirely different impression on me in person than on-line. Ditto every other person in the group that I met while you were in Paris.

Did you get the same (i.e. reciprocal) feeling?

I think this generalizes: in many contexts we present a specific "persona" that may or may not be consistent with the ones we display in other contexts.

There are techniques for giving useful and actionable feedback. (Here's one good book I've read on the topic.) We may consider this topic as belonging to the "self-help" reference class, and infer that nearly all such techniques will be backed by very little hard evidence and lots of speculation.

So, to the extent that norms for feedback lead us to ineffective techniques for soliciting or giving feedback, they may do more harm than good. But I would approve cultivating a norm promoting effective asking and giving of feedback.