Interesting the engine should have a 1200 hr TBR, so if it was replaced at 500 hrs I am guessing it was having problems. The 1.7 has a poor reputation for reliability and maintainablity . There is a reason there is a Thielert 2.0. In particular many 1.7 engines had significant cylinder and piston problems at the 500 to 600 hrs mark. In addition the gearbox only has a 300 hr life.
Personally I don’t see the upside to operating this engine. Yes I get that as a home built you can ignore a lot of the maintenance requirements but these came about as a result of a spate of failures, fortunately mostly in the DA 42 which as a twin meant the airplane still made it home.