Hans, my apologies for this late reply and thanks for adding your sound advice.

I am in no way qualified, however from what I've learned about NACA's early studies - and read about Harry Riblett's work - I couldn't agree with you more.

There's a super article about Harry Riblett here, for anyone interested:
https://www.kitplanes.com/the-airfoil-adventures-of-harry-riblett/