It is also tribal knowledge within the home building community, to those that have been involved for quite a while.
IVO attempted to introduce and market his prop design for use on lycoming engines ~25 years ago or so. There were a lot of failures and some design changes made in an attempt to make it work but they never did.
A 4 cyl Lycoming has far to strong of power pulse cycling for the prop to endure.
They work fine on smaller displacement engines or engines that have PSRU's that act to damp the power pulses of the engine.
Any opinions expressed in this message are my own and not necessarily those of my employer.
RV-6A (aka "Junkyard Special ")