Phil, great work and thank you for an excellent go at documenting the progress and your findings. At the risk of asking the obvious, have you reached-out to anyone at Centa or MMC to discuss your work? I would think Centa would have a vested interest in the inserts and may be able to render an informed opinion as to relative merits of your revisions. As mph noted, the changes to the "shock absorbing property of the Centa coupling" may be of concern to the rest of the drive train, or not.
If your new poly blocks effectively reduce the Centa cushion action, what problems does this actually cause down-stream? If it was just eliminated entirely, what would happen? I could "imagine" accelerated wear in the trans splines due to the irregular power pulses, bearing failure perhaps, or maybe no real problems as the trans is robust enough to handle it? Perhaps this has been discussed before, if so, sorry for re-hashing it.
