Liv, you've got a lot of choices in how to communicate with this man. I've found that saying something directly to STBXH in the moment works -- for the moment. He often says, "You never told me that!" when clearly I had. I have adopted this strategy. If he asks me to do something I don't want to do (change my schedule to accomodate his) I say no. If he pushes, I send an email, reiterating "no." If I feel hurried to make a decision, I say, "I need some time to think this thru." Then, I respond at a later time via phone or email.
I've just learned documenting my boundaries works with STBXH, but not in a laundry list -- rather, as things come up.