I would propose that the Tree Farms take out leaves as well as logs. When a tree farm is allowed to grow in a patch of grass, the Leaves grow super close together, which causes some major time lag, on servers, I am unaware of this occurring on single player. A semi-workaround right now is to place spaces between the saplings with placing a non-dirt/grass block in the tree farm, but, if the lumberjack gets overwhelmed by the speed of the tree growth, the leaves grow in quickly and lag the whole server down

You can checkout undesired work blocks in the "bounds" GUI of the farm.
Darkened spots will be left alone. (no planting, no harvesting, etc)
You can also put a shearing item in the special resources inventory, to get the leaves sheared.

That works, thanks!