Anyone?... *crickets chirping*

I'll preface this by saying I'm no expert and this is just an uneducated opinion based on my experience. The avocado and citrus should be trimmed to a lollipop shape or very rough proximity of one. The open vase has the potential to allow too much sun in and scald the trunk and main branches, damaging them and opening up the possibility of insect damage. These fruit trees are tip bearing so the more outside surface you have, the more fruit is exposed to the sun. I haven't grown the mango or mulberry yet.

I have seen some short pruned mangos fruiting. There is a picture of a greenhouse mango farm in Japan growing Irwin Mangos on trees that look 4 feet tall and 15 feet wide covered in fruit. So, I guess you can prune a mango how you like.

I can't seem to find a good answer on mulberries though. Just looking online, some say you should almost never trim a mulberry tree because of bleeding from wounds. Others claim they coppice their trees (on own roots), but leave about half of the 2nd year branches for fruit.