I tried running all 4, then just two, and eventually went back to the standard. Poly is effective at controling the spinner/cowl alignment and sag as expected but just a bit too harsh for a long cross country ship in my opinion. If it was a 30 minute per day acro ship, then I'd use them.
There are different formulations of poly that might work better, but its going to be a while before I have the time to machine up a mold and experiment.
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.
Harmon Rocket II -SDS EFI instalation in work
RV-8 - Flying
1940 Taylorcraft BL-65 -flying
PA-20-inspired "family truckster" -in work