As an IR certified PPL(A) I will confirm the fact that simulated IMC is very different to proper IMC, particularly so when flying solo.
I have only flown a heli a few times under instruction (R44) but am curious if it is even possible for a very competent IR rated heli pilot to safely fly a non certified (for IMC) helicopter in these conditions?
As shown I have seen the youtube hero who made videos doing this, and is now dead, but surely it is russian roulette at the best of times? One thing goes south and the events chain can very quickly build up to catastrophic levels as shown in this tragic video.
Truly terrible - RIP to the people onboard.