I don't think the issue is the turbine but rather the appropriateness of going to a 407 directly. I learned to fly helicopters in a Jet Ranger, at Bell, and after about a week, I was flying their Jet Ranger solo across the Texas country side accumulating the hours required for my rating.
I haven't heard of Bell doing the same thing in a 407, and they know a bit about helicopters and teching folks to fly them. I have also heard of someone telling FlightSafety they wanted to go from a 182 directly to a Citation X, and even though that is a two crew aircraft (so the person would be more or less "supervised"), Flightsafety wouldn't do it.
Unless the 407 initial is just an exposure to the aircraft, it would make a lot more sense to move to a Jet Ranger, build hours, do recurrent training, and get comfortable in the sky before adding the performance and complexity (overall check list, fadec and hydraulics off) of the 407. That would make the insurance company happy and make sense to anyone evaluating your development as a helicopter pilot.