In my neighborhood either the majority of sukkos, or at least a huge mi’ut use a pergola for sekhakh. They make pergolas that are sukkah friendly. The slats rest in slots, so it isn’t one big board - and run afoul of gezeiras tiqra, and the slates can be moved after the walls are up - so there is no taaseh velo min haasui. Mine has a non-wood top that can be easily removed for sukkos (wingnut screws).
Today I was at a chaburah-sized shiur taught by R Moshe Willig, and as he was wrapping up mentions that his father doesn’t think they’re kosher. Our discussion of the topic as he was leaving was rushed. But it sounds like R Mordechai Willig is mostly concerned with the slats warping over time and becoming warped enough that they are wedged in. So, I asked the younger RMW if he could remember to ask his father whether the lid my pergola wears 51 weeks a year is enough to reassure him on the wedging issue. And is that his only issue?
That said, the initial rav of my shul, R Avishai Chaim David, permitted. Meaning, my neighborhood actually got a pesaq that all those families are following.
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* RACD is RY of Toras Shraga and after us has been the LOR of a shul in RBS-א. He was a talmid of RYBS for some 14 years. (Leaving my shul with a lot of Gra-, Brisker-, and RYBS-based unique minhagim.
And the current LOR is not interested in overturning any of it, even though he is not Litvish and personally would have ruled quite differently. Might be worth discussing if he is halachically empowered so.