> what you do next time you’re in Oklahoma
> daven beyechidus rather than in a chabad shul,
First, I presume you will have mashihists in some central locations, but in Oklahoma the only person who might be one would be the shaliach himself, the rest being pure neshomos. Also, what is the probability one needs to be hashash for? We do have examples from Mishnah when we silence hazzanim who daven apikoires, so it was not unheard of to happen to be among some sort of unorthodox opinions. So, why can’t you go there and leave you hear something inappropriate.
FWIW, once at a wedding, a bunch of Chabadnikim started dancing “moshiach, moshiach” and my Teacher from Lakewood, who is a little big in all dimensions, got up, held the chief Chabadnik in his hands and circled him around until the other guy fell of exhaustion. I presume to show that we all are pro-Moshiach. He davened with them also. So, your Rav may be an outlier.
When unorthodox opinions are vadai, then you are right. R Soloveichik rules that one can not go to listen to shofar there.