Unfortunately when I select a location for a biter to expand to, and then select a biter, this error pops up:

The mod Friendly Biters (0.1.5) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event FriendlyBiters::on_player_selected_area (ID 51)
LuaUnitGroup API call when LuaUnitGroup was invalid.
stack traceback:
[C]: in function 'index'
__FriendlyBiters/control.lua:179: in function <FriendlyBiters/control.lua:111>

Edit: I seem to have identified the issue, when you select the biters you want to perform the expansion, if you didn't make a large enough square, the error pops up.

Also, interestingly, the new nest won't go where you specifically selected it to, instead it'll just go in the top left corner of the green rectangle that comes up when you select your biters, very strange.

Awesome mod otherwise!

Trying to use the controls, i cannot tell if the biters are even selected. But assuming they are after they are highlighted yellow, they respond to expansion and to move. But make sure to re-select your biters else ANY kind of move or expand will result in a soft crash..

Unit Control works flawlessly with this, with the only caveat is the 'expansion'. Enabling Unit expansion makes it so i cannot select the biters at all with the built in blueprint items without crashing however..

I can make biters move, guard, waypoints, follow..ect. But i cannot get them to expand unless i turn off Unit Control.

I have fixed the first 2 issues but I dont know what you mean by 'enabling unit expansion'
in the current build the expansion point system isnt working so you should be able to expand as much as you want

Unit control and THIS map conflict.. IF i use Unit control, it errors out. IF i do not, it goes away but i lose a lot of the functionality of Unit control for the other entities.

I was able to reproduce the issue and I dont know if I can fix it.
When you select the biters using my mod it creates a new unit group, for some reason if the biter was selected by the unit control mod the unit group is invalid but the validity check returns true.

You can work around this by somehow not using my mod to select biters after they have been touched by unit control, but you can use unit control after my mod controls the biters.