You may want to look into finding a patient advocate to help you.

Ombudsmen: Front-Line Advocates for Nursing Home Residents

I find it hard to accept their objections to better pain management. Especially since you have an option that works. Maybe his primary care doc can step in.

So many get hung up on "standard protocols" , which do serve a purpose, but too many times they become too rigid in their ways.

Here's an interesting article on MM in nursing homes:
The Nursing Home With A Medical Cannabis Program The Feds Can Live With