RE: DL-50 engine
Ditto here...no running in was necessary for any of my DL's (have 3) or my DA's for that matter. Just run one tank through on the ground to makesure the idle is reliable...then go fly....as hard as you like. Worked for me.
I also ran 50:1 synthetic straight out the box on all 5 engines (3 DL & 2 DA).