Well, intelligent debate is always a good thing.
And Blizzard, I congratulate you on your patience... for a great many things

Since this has come down to that, I might as well submit an idea I had.
It vexes me when I go back to a map I just cleared to fing it once more choking full of monsters.
In the project I'm currently working on (I think it's my 15th epic fail so far) I use an evented time system.
Whenever an enemy is defeated, it vanishes and does not "respawn" intil the next day. It requires some switch micro-management but works for me.
Although I'm not using an ABS, that's where it would work best.
Respawn times can get as detailed as the time system is, or even different for each enemy event.
I could do that myself, except that my skills in RGSS suck. The fact that my knowledge and expertise ends at linear programming makes me feel kinda retarded