-@ No hoper , Yes, but the burden of all the early development costs was borne by those who lost their shirts, either directly swallowing a pill (taking an unpleasant loss) when Thielert folded, or buying a lemon powered by the troublesome, costly and maintenance-intensive early engines.
the new owner has , really, only the refinement costs to fund. That makes a huge difference to the profitability of the new product and also the legacy engines could well be a cash-cow, as the poor aircraft owner is well and truly caught by the gonads.....pay the ransom-price to keep the engines running, scrap the aircraft or , lastly, go through the process of converting to a different engine and getting certification.
Harmonic dampers are well-established in the automotive world, I don't see any issue with C.I engines for Aviation use...As has already been alluded-to, cold and thin-air are bigger things that could slow progress whilst their potential threat is eliminated.