We have had a couple threads on the subject and all I can say is that in my head PbtA and FitD games are similar but ultimately different systems -- like 5e to PF2 similar but different. But that's because I investigated them simultaneously but separately, rather than going from one to the other.If we're calling Ironsworn PbtA, I would also put Scum & Villainy on this list, as it's derived from Blades in the Dark, which is derived from PbtA.
As to Ironsworn: I don't know if it is PbtA but I really like its core mechanic as presented in Me, Myself and Die season 2. I have not gotten around to trying it, solo or otherwise, but plan on stealing the d6+mod vs 2 separate d10 DCs thing.