When I sleep in an Abena, I also have an Abena Abri-let Maxi stuffer. It's about 2 feet long so I fold it in half and put the whole thing up front. When I do controlled wetting in bed in diapers, I'm face down and the diaper-stuffer combo can take quite a bit. And it holds it, too, regardless of subsequent sleeping positions. I might squeeze out enough for a small damp spot but that's about it.
But if I'm on my side, whether sleep-wetting or wake-wetting, if I flow fast enough and some pee runs to the side, all it encounters is the side plastic. If I were to really get into regular bedwetting, I'd have to look into cloth for more all around protection as I am a side-sleeper. It probably wouldn't hurt for me to invest in plastic pants, too.