I don't remember if NPN worked or not, I'll try to test it tomorrow, I'm building a negative regulator. It's interesting how easy it is to get the negative voltage, same circuit, just move the negative feed, (ground) to the point between the inductor and the capacitor. A problem I have is the lack of higher voltage power supplies. I do have a Variac and I guess I could put a bridge on that. But that has no isolation. I got to see (hear) a 22uF 100V cap fail today, haven't found the canister and there was paper everywhere. I kind of think it got hot because of it's proximity to the 100 ohm resistors.
I just simmed the circuit with a NPN and it does run, (last attachment)
Since I'm always hands on with my power supply usage and it does have definite limit, I don't think I'm going to worry to much about current limits, If I find a need for it, I'll just use a LM317
Yes be very careful for sure. See if the PMOSFET gets hot too. But then again for much higher DC buss level you'll need a higher voltage PMOSFET too. Hope you have one around.
I like to stand back several feet when i do tests like this.