I disagree that you should use a No Pest Strip this late. There are nasty chemicals in it. Especially don't use it during drying. If you must use it, use it for 5-7 days, then take it out, and add heavy ventilation and let it air out for several days. I think sunlight (and possibly HID light degrades dichlorvos, the active ingredient, rather quickly). I sure as fuck don't want to smoke buds drying in a dichlorvos saturated room! If you want to smoke it yourself, fine, but don't put others at risk unknowingly. I use mine at the 12/12 switch and then remove it from the room after 7 days.

Its really odd that your plants aren't ready yet. Are you not seeing the amber trichs? Sometimes they're just tinted and not blatantly amber. At this stage you just need to keep the mite population in check. I would try environmental controls: turn the fans on high 24/7, lower temps to the 50s at night, raise humidity if possible (may decrease trich production), spray the undersides of leaves with water. Do things like this and you should keep the population down so they won't attack your buds. I think they stop reproducing below like 60 degrees.

I've also heard that spider mites won't be interested in dead/dying plant material. So once you pick your buds to dry, they quickly won't be interested in them because they can tell that they are dying. I've also heard that they climb up the buds when they're drying and climb across the drying line.