Yep, 2.5 turns is likely not good. The fact you are able to drown it like that does testify to the fact your fuel passages are all open though?

The 'high idle hang' is caused by a hot combustion chamber. Nothing else will do that. The engine is actually in a 'run away' condition, and will stay that way until it cools off. Normally, you can cool that combustion chamber down tossing fuel into it using a fat low speed mixture, but if that's not working out for you, you can go after the reason the combustion chamber is so hot? Maybe the high speed mixture? Could be a too small prop? Engine sucking air somewhere? Try running minus the cowl? If you can rule those issues out, is the engine still under warranty?

I like the plan of starting over from step one with a solid tune starting from 1.5 turns high and low. It costs nothing but a little time.

For others having trouble with that hang, if you have a DLE 20 - there is that timing issue which is very similar, but that's on 20's only. No other module has timing issues. Period.