My 23

[Fr. Frank]

Ken? from Prop Gods regarding spinning props inward, and he agreed that it can yield positive results in some applications. ...
It is just impossible to say what will happen until you try.

I'm old school, and have been out of the high performance field for almost 20 years. I never tried spinning inwards, I just believed the engineers who told us why it was a bad idea. I do know that with that Rybo Runner we switched the lower units on, we pick up quite a bit of performance by changing over to spinning outwards. But a Rybo Runner also had a 10' beam, with the motors mounted a full 4' apart, center to center.