hi,
When using the “add single support” command (by using icons) the command stays persistent, meaning you can continue positioning several supports while still being in that same command…
however,
When using the “add tree support” the command interrupts each time you finish a tree support, so you need to reclick the icon, each time when you need a new tree support.
When you do hundreds of trees per day, it kinda gets tedious… 
Not sure if it is a bug or an oversight, but i’ll report it here anyway…