Look at some of this stuff

https://www.bing.com/search?q=mango+training+pruning&cvid=f027fbf034a64cf692e3d28f0bcbc226&FORM=ANAB01&PC=U531

Is there anything in there that answers my question?

I'd probably remove them to open it up for better air circulation, but can we see the entire tree? Is the tree height such that you can easily harvest the mangoes? Are you at all concerned about tree outgrowing your space?

Thanks, Dave. Air is good, especially in low portion where those branches are and would be for a long time. Tree height managed with pruning. Unconcerned about space. First thought was of their taking energy, little now but more in future. Then I thought of future, that these could become productive, perhaps taking over for old ones that I might choose to remove.