Q. What are the parameters of sofek berochos lehakel according to the Mishna Berura. would this apply even if we have the majority of opinions say to make a beracha and only a few poskim say not to?
Thank you

A. Shulchan Aruch (O.H. 215: 4) rules that one who recites an unnecessary brocho transgresses the commandment of “Taking His name in vain” and is tantamount to uttering a false oath. Mishna Berura (ibid.20) explains that the source is the Rambam (H. Brochos 1: 15) and the Talmud (Brochos 33b.) However, he mentions that other Poskim disagree, and maintain that one only violates a rabbinical prohibition if Hashem’s name is pronounced unnecessarily, when done in praise. He also asserts that when in doubt, all agree that unless it is a biblical brocho, no blessing is recited. He adds in the name of the Chaye Adam and Pri Megodim, that even in a S’fek S’feiko case, when an additional permissive doubt is added to the questionable brocho, no blessing should be recited.
Horav Shlomo Miller’s Shlit”a opinion is that in practice, whether you recite a brocho or no, depends also on the accepted minhogim of each place and congregation, since some may follow the opinion of only a minority of Poskim and still recite a brocho.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a