Not so complicated if you focus on the kids and give W rope. Just observe what she does and document. But you also need to be able to show that you objected when she did it, because you have to be accountable. Just don't expect anything from her, it's merely something you have to check off on your list.
"W, I noticed that you took most of the children's clothes from the house. This is in breach of the parenting plan. Please bring the clothes back on your next return. Thank you, Jim."
Then don't expect her to do it, or expect a negative reaction. If you get a negative reaction, just say, 'okay', then document again. "W replied to my request to return the children's clothes with "Blahblahblah" via text on xday at xx:xxpm."
Was it her responsibility to get the studio apartment, or were you both supposed to get one rented and stay there when you are not in the house?
M 16 yrs, WH62, P54 3 adult blended kids EA 11/13, BD1 6/14 PA fall 14, BD2 2/15 Piecing 2015, BD3 12/15 Separated 4/16 WH moved OW in 5/16 Divorced 6/15/17