Should I cut this Mamey down in height ??

[Johnny Redland]

This pantin (key west) mamey is growing very vertical. Does anyone see any disadvantage to cutting about 3 or 4 feet off of the top? I’d like it to grow more symmetrical

[Das Bhut]

I've cut a lot of trees down to a foot above the graft for the same reason. When I did it to my Pace it flushed out a few new branches, and all of them are just growing straight up anyway.

[Rob P]

It is still a young tree, give it time to spread. Always cutting young non-bearing trees just keeps them in a vegative state, the plan is normally to get fruit as soon as possible.

[Finca La Isla]

For what it’s worth I don’t agree with much of that.
It makes sense to properly shape a Mamey sapote tree as it develops.  These can become huge trees easily and that will make the harvest tricky. 
As the young tree is growing you can simply break the terminal bud off, forcing the tree to branch out.  To harvest these fruits we want to be able to scratch the skin, check the color underneath. 
Shape the tree to have a uniform amount of branches, taking advantage of the space you have and don’t let the tree go over about 5m, 16’.  The tree in the photo should have about the top third cut off and perhaps some other branches could be trimmed back a tad to encourage better branching.
Another thing when shaping like this is to make sure the sun hits the side of the tree because if it doesn’t it’ll be harder to keep your Mamey from just trying to go straight up.
Peter