My point is that whichever you choose to use in the Buckingham Pi method is irrelevant.
The "unknown constant" that Buckingham Pi cannot solve for just absorbs or corrects for the divisor of 2pi.

If you can show me a derivation of the Planck Length that is based on physics, and not math, then maybe I'd have some hope of interpreting the meaning of that value. But w/o any physics attached to the derivation, any physical interpretation is speculative.

The notion that the Planck Length represents a lower limit in space beyond which our current models make no predictions seems sound, but I haven't actually seen a proof that it is so. Certainly nothing which resolves the h vs. hbar vs. some other unitless scalar multiplying the result in question. It's just sensible to note that our model has limits, and if that is one of them, then I can accept that.