I'd push for a hematologist or new cardiologist on your mom's team, Sue. There are multiple options for anticoagulation when there is an ongoing need to control bleeding risk, even given the option of a permanent drain (which might carry lower bleeding risk than repeated procedures). Bridging protocols are changing as well.
Also, the new guidelines for many GI procedures permit more latitude than 0-60 depending on non-procedural as well as procedural risk factors. Trading off bleeding risk is much more individualized than it used to be, with new agents in the mix. I've attached an example of one hospital protocol.
If she is ready for hospice for other reasons, that's one thing, but to go into it for reasons of anticoagulation would seem to mandate careful consideration of all the options.