I had some more thoughts about the planche. Of all the gymnastic exercises I utilise, most can be rationalised from a paleo perspective - they are of a climbing nature such as muscle ups and levers, or they are rooted in 'play' such as handstands. Even exotic gymnastic exercises are 'bastardised' versions of basic movements.
But then it occurred to me that the planche may well be seen as one of THE most fundamental exercises.
With babies you are recommended to put an infant on its front for a period of time as soon as it can hold its head up. (You can see where this idea is going). As the child develops it then progresses to sitting up unsupported at around 7 months and then eventually to kneeling, then pulling up to standing (assisted) and then to crawling.
You can see that several of these stages involve arm, shoulder and back strength similar to those targeted by a planche. Such strength in an 'all fours' position is evident in most if not all land based mammals.
So maybe the planche is actually pre-paleo. Maybe the gains we can get from it are rooted in our evolutionary past on all fours. I would love for someone to look further in to this idea.
Enough of my ramblings. ;)