If its only the trombone you need from that channel, you could EQ it to knock down the upper mid harmonics and make it considerably less grating.
If that's the SBD intended to be matrixed in for more than the bone alone, then its harder to get away with doing that without screwing up everything else along for the ride in there.. yet if there is little to no bone hash in the other matrix source, you might be able to EQ that alternate source the other way to tonally compensate for whatever bone moan correction you feel is necessary in this one. Takes listening and adjusting the two complementarily EQs iteratively until you get it dialed in, which might be more effort than you care to spend even if it works.