In version 0.3.5 of this mod (most recent as of posting) a crash occurs. It appears to be an edge/timing case. When the shield generator attempted to recover/recharge a shield on an entity that was getting destroyed at exactly the same time.
stack:
Error while running event shield-generators::on_tick (ID 0)
__shield-generators__/control.lua:807: attempt to index local 'tracked_data' (a nil value)
stack traceback:
__shield-generators__/control.lua:807: in function <__shield-generators__/control.lua:590>