Diamond didn't look after their customers last time round. Why would they if the Austro went wrong.
AIUI, Diamond were able to walk away from a % of the Thielert engine liability because the original aircraft were sold with separate warranties for the airframe and the engine. Under EU law this is unenforceable (it is IMHO obviously illegal to do such a stunt) on a private user, but many were sold to schools and they had no recourse against Diamond for engine issues. This is what one FTO owner told me.
This time round, if they get any trouble, Diamond won't be able to do that. What that means, one cannot tell. If there is a small amount of trouble they will have to deal with it. If there is a lot of trouble, they won't be able to afford to deal with it and will do all they can to wash their hands of it.
I don't know any Diamond owner who would trust the company (
in Europe) as far as he can throw them, so the issue is really a bet on the reliability of the product.
OTOH, I bet Diamond looked after their American customers a lot better. They have to.... trash your reputation in the USA and it is game over, for ever.
Will they do a diesel version equivalent of the IO540?
I recall SMA (now owned by Continental) were doing an IO540- engine mounting compatible diesel. Oddly enough Socata do have a TB20 flying with it, and have had it for about 10 years, but the project was abandoned, reportedly due to severe vibration issues.