Wow, freshstart, what a situation!
DW has a friend in hospice now with a similar prognosis. After three weeks she's already exceeded the time they thought she'd be able to be off her cancer-treatment meds. Similar issues with juggling which drugs are allowed and which are not as well as decisions made by the patient and family (do they really need to ride herd on her blood glucose levels now?). What I know of her situation, though, is that she's no longer on the expensive drugs.
Not to just do the "guy thing" but I take it you have the legal power to represent your mother in this matter? There should be some sort of appeal mechanism for decisions like those (if there really isn't, there ought to be). For what it's worth, I can understand your mom's reservation in taking on the hospice, but what I've seen with hospice in other situations is that -- at least at a basic level -- the care level is the people who show up, not the panel sitting in their offices. There's only so much they can do to mess up her care.
I wish you the best. Not only is there the matter of your mom's last days, there's this battle to fight as well....