We don't have a hybrid, but I think my idea would work for anyone in pretty much any type of trailer.
We started camping when our littlest was 8 months old. There was absolutely no floor space in our trailer for our pack n play, nor was there room to set it up on the kitchen table. In the beginning, we just That worked ok at night or for some naps as long as I rocked him right to sleep. By the middle of the summer, it was no longer enough to keep him in bed. One afternoon, I put him to sleep on the bed. At that time, he had not been able to get down from the bed by from himself or open the door to the outside by himself. I even locked the door from the outside thinking there was no way he would be able to work the lock and the door handle! I then went to our friend's trailer right beside us to visit, taking the baby monitor with me! About 30 minutes later (he usually slept for 2 hours), I went back to check on him and found him OUTSIDE the trailer and playing with the ice in the cooler at the bottom of the stairs!!!!!!!! At 11 months old!!! It's scary to think how that could have turned out. We knew we had to do something to make sure that this never happened again so we bought one of these.
We placed this PeaPod sideways on the double bed so it couldn't roll off, but you could probably use a bed rail along with it if that doesn't work for you. By squishing it down a little, it easily fit on the bed under the upper bunk. For added security, I added a key ring to each of the zippers and used a small carabiner to clip the zippers together so that he could not let himself out. We used it until he was 3 years old! There is no way he would go to bed at night, or nap in the afternoon, if he could get out of bed by himself.
Another bonus is that it packs up super small and doesn't take up much space when you are not using it. Way less than a pack n play. Definitely get the larger size if you plan on using it for a toddler though.
Hope this helps someone, it was perfect for us!