Our primary bass in big band plays a Blessing 88H (?) with a 1.5 megatone mouthpiece and covers the part just fine. We sometimes run two basses as per N TX ST. The 2nd bass has a Thomas that is a true bass with two valves. It makes for a good sound.
One of our 88H one and only players got called to cover bass in Michael Andrew’s big band. With the Remington supplied mouthpiece, which he sounds great on for anything else, the big band bass sound was not achieved. The looks he got from Michael Andrew were not endearing.
The time I got to play Brahms 4th in university I was using an 88H as was the 1st. I confess that I loved the sound. The 88H and 2B achieve a respective quintessential essence. If chamber music and brass quartet and quintet music were more more popular, a 0.525 might have found its niche. Perhaps the Bach 36 or King 3B+ did. I don’t know what Brahms heard when he wrote it. It is quite possible that 0.525 bores would cover 1st and 2nd. I would even be interested to hear Brahms 4th played with Bach 6s.
There was an old guy playing 1st in the old Tulsa Philharmonic with a King 3B+. Some college punks made fun of him. I did not get to hear them play Brahms 4th. But I actually thought he sounded okay. At least it did not “stick out.” Actually it was better than okay. I liked it better than some of the orchestras with trombones that sound more like euphoniums.
And Yes: Trombone Chat is probably dominated by players with obsessive compulsive disorder.