That “Frequently.” is supposed to be an answer to both questions? Please use quote system next time, this was confusing as hell.
I asked, because this whole idea screams of “All I ever did was mining in highsec and I want to make it a bit more challenging because I am bored”.
Mining in low and null is much more interesting because the npcs are stronger, comes much more often and can even warp disrupt. They also have nice loot and every npc drops a loot so it is actually solid extra income.
What do you think will happen when all these solo miners or players with weak skills to not fight the npcs let them spawn and switch a belt? Eventually now they occupy all belts.
No this suggestion is simply terrible. I am sorry. And no I am not one of those nay-sayers who automatically shutdown every suggestion posted here. Here is a well written player suggestion which I do support - Fail Conflict Drivers Feedback (ESS Reserve Bank, Skyhook, and Mercenary Dens)