Great fun watching this very cool video

Nice pitch control!
That sounds like it might be a Subaru. I hope OREO pays Liz well if they make a TV commercial with your video.
Not to spoil the fun , but I had a neighbor with a Piper Lance ( IO 540). He would often do the zero g thing for his passengers.
Me being a mechanical nerd, I could not help but watch the oil pressure drop into the bottom of the red zone, during the brief 2 -3 second zero G parabola. I did not say a word as the PAX were having way too much fun. Within a year of my observation his AMO shipped his 540 off for rebuild as it was producing too much metal in the filter. He flew a lot of different people and I have no idea how many repetitions he did, but I have to assume it was done on most flights for laughs and giggles.
A lot of fun aerobatics can be done with no loss of oil pressure, however I don't do this one, even as hilarious as it is to watch. YMMV
I think the RV is very tight for a Heimlich if ever it was needed.