First HFWO

I want to start by saying I have kind of always been a bit intrigued by the idea of having a HFWO. So to make a long story short in late June I added a ProJ to my tool chest and the first couple of times I tried it I could tell it was different. Now jump ahead to last week and my last session with the ProJ at the very end at about the one hour mark I could feel something start to build that I had not felt before. I became semi erect and kept building to the PONR getting closer than ever before without ejaculating. It felt fantastic! Then this morning I took it for another ride and OMG! It gave it to me fast and hard for an hour. One SO after another till I was ready to stop after an hour. Just as I was ready to end the session I felt a little tingle and started to get erect. It felt like a TO but in slow motion. What would normally be over in a blink of an eye just slowly continued to build getting closer and closer to the edge. I really wasn't expecting it to take me over the edge but then it did. It didn't shoot out it just kind of oozed out like it does sometimes during a edging session. I hadn't ejaculated in a while but I still feel horny right now a few hours after the fact.
So I'm not sure if I should consider that a milestone or a cause for concern. All of my other sessions with other models still seem to be going as normal. Great prostate centered SO's only the PJ seems to have this effect so far. Does anyone else have this happen on a regular basis and which models does it for you? Can you control it and make it last longer like edging before it goes over the top? Can you have multiple HFWO's or does it mean the end of a session once it happens? How does it effect SR does it start a new cycle?