We're both very tired of uBPDbm leaving SD9 home alone. We're going for majority, but right now I'm wondering whether we should go for no overnights.
That sounds reasonable. You can throw that into the motion as an FYI. "BPD mom left SD9 home alone on x, y, and z occasion. Here is the call log, texts, and behaviors that worry us." We request majority time and no overnights.
That's why picking up SD9 might work in your favor. It makes it concrete. "We got a call from SD9 at 12am and she was scared. We came to wait with her until 1am. When her mom had not arrived by 1am, we felt it was best to take SD9 home until we could be sure BM was going to return for the night. This happened again on day/date, day/date, and day/date.
It can't hurt to ask for it.