I have a Rovner EVO-5 that works great on my tenor Otto Link 6* STM, it's an E-2M. I like a darker sound anyways so I was prepared to experience a bit of damping but actually, it was quite the opposite. It opened the sound up a tad and seals the reed against the table much better than the original OL lig. Well, at least the way I use it anyways, YMMV!
The EVO-5 has been discontinued by Rovner and replaced with the Star Series. An SS-2M should fit your Berg Larson iirc.
I might pick one up for my an tenor STM NY I'm playing around with!
Happy hunting!