I play a Besson Sovereign euph and have landed on using the Wick 4AL. Tried the Schilke 51 D, 52 D, 52 E2, and an ACB 1, The ACB 1 was better for me than al of the Schilkes, but the Wick 4AL helped me more in the high range, where eups flourish. I will say that I struggle to focus everything in the mid-range on that 'piece, but I think with any mouthpiece the player needs to adjust to what it does. The euph is a 1995 model of Sovereign with a .80 bell thickness. I don't know how that year differs from a 2023 model, but the Wick 4AL seems to be pretty ubiquitous in use these days.
The University of Missouri "University Band"
Columbia Community Band, Columbia MO
Trombones:
Shires .525 medium bore
Conn 6H
Euphonium:
Besson Sovereign 967 Satin finish (1995)