Crib Elevation

I have always elevated my son’s crib. For the last few weeks, he has made his way to the bottom of the crib within a couple of hours of being put down. He ends up completely horizontal. His head is in the bottom corner and his feet are at the other bottom corner. I know that it only takes a couple of hours because I watch him on the video monitor. I still have crib bumpers so I am worried that this horizontal position is dangerous. He also does not get the benefit of the elevation when he ends up horizontal. So, I am considering de-elevating the crib. He has never really suffered from night wakings and he chokes during the day sometimes when he tries to talk, laugh, eat, etc, but I have never noticed it in his sleep. What are your thoughts on de-elevating the crib?