Hello,
A couple of days ago we started a run with “Glory to Greed!” curse (no item pickup, but hexed enemies spawn a didgeridoo piñata). Early in the level we avoided a stormvermin patrol (in which I noticed there were hexed enemies). We didn’t encounter a single other hexed enemies on the map, neither before the patrol, not after the patrol, leading to no pickup (and no coins), which does not make the run easier.
My suspicion: There is a limited maximum of Hexed enemies alive at a time, and the patrol took all of the slots from the start of the map until the end, preventing any other from spawning.