[please forgive my poor English]
Regarding the question in the OP, things have have become more simple for me, at least in
one of Brussel's concert hall:
it is now (unofficially?)
allowed to switch seats after the pause (there are no written rules though).
So,
YES, I do it whenever it is useful, and possible. And my personal ethics is relieved to do it "legally".
Impact on the listening experience at home?
Switching seats, if possible without harming anyone, sometimes deliver revelatory sonic delights.
For instance, last season I switched my seat to sit nearly "above" the outstanding violin player from The Netherlands, Janine Jansen (Beethoven violin & piano sonatas, piano Denis Kozukhin, winner of the Concours Reine Elizabeth international contest 2010). Mrs Jansen plays with an amazing instrument: the Stradivarius which belonged to Nathan Milstein. I never heard a violin which sounded like that one before (see also her disc: 12 Stradivari,
Discogs)
Switching from here to there was a revelatory experience for that memorable concert, one of the best I ever attended.
(elliptical concert hall designed by the Art Nouveau movement founder, architect Victor Horta)
But sometimes, it is fully booked, and no switching is possible:
(last Friday, the opening concert of the 23-24 season, Beethoven concerto piano #5, Leif Ove Andsnes - bad seat, 4th row - last season, I heard the same Andsnes on Janá?ek and Beethoven sitting row #8, it was wonderful; always slightly at the right of the piano for better sound - it is Andsnes himself, with the musical Director of the hall, who had chosen the Steinway of the concert hall, in Hamburg)
In other concert halls, switching is not allowed.
For instance, it is a safer bet to buy the best seats in the (new and positively outstanding) Namur Concert Hall, already considered as one of Europe's best. Labels are already rushing in to record. On row J/K/L, you really wonder if you're in the 4th or in the 5th dimension. This place is worth a trip to Namur, not kidding.
Stellar shoe-box. Built in 2020 (designed by Kahle Acoustics, Brussels - amazing pics of their projects
here)
It's simple, there is no place (that I know), other than the Namur Concert Hall, where I could hear so "physically" the texture's density of the instruments (except when I sat just besides the violin and the harp, when my cousin and her daughter are playing; but this is no concert).
I also attended a "funny experience" (not really a concert either), organized by the Concertgebouw Brugge: audience sitting inside the orchestra, besides musicians, as if we were part of the orchestra. They called it "Surround" (
pic). The purpose was to trigger interest in a younger audience. There I could here textures of an unheard density too, though it was unbalanced. I sat carefully away from percussion and brass...
Distance from the orchestra is nonetheless necessary. But such "experiences" helped me realize that with distance, a part of the "density"/body of the instrument's sound is kind of being
"sublimated" (solid -> gas). This reinforces my tendency to not lower my demand for "body and flesh" (though to match those with speed, transparency, "breathe" and life-likeness, is quite another story...).
There is no other concert hall I know than the Namur Concert Hall where I could hear instruments delivering textural densities and richness of timbres, along with a superlative intelligibility of voices (the hall was built as a tool for choral music, but all genres can be played comfortably), while sitting in the audience, not in the orchestra, and not too near from the stage.
Recent exposure to instruments playing in such a high quality acoustics, seating in the best seats, somewhat reset my aural compass and, I confess, event gently triggered my interest for good horn speakers (not the one that "shout", stress the sound or sound with cupped hands).
I can say that, to a certain extent, it helped me reassessing some audio gear or systems, too. The now allowed
seat-switching-after-the-pause in the historical, very good-sounding, historical concert hall (pic above), helps that too, in a different way though as the sonic rendition is slightly warmer there, and gently verges to the "comfortable".
Last season, I attended 36 concerts. Most of them in the best seats (sometimes switched).
Music: what a marvelous "hobby".