That’s a wise way to handle it. Good thinking.
You (and he/his family) might also consult cholangiocarcinoma support forums. In my experience, you often meet very smart well-informed caring and generous people in such forums who have done extensive research, share their experiences, etc., wealth of info — and offer the kind of emotional support only those who have “been there” can. In many such forums, medical specialists and researchers in the field pop in and share information as well.
Here’s one such forum:
https://cholangiocarcinoma.org/db/
You can do an internet search to find others if you think it might be helpful.
Oops, forgot to mention these forums are like gold to family caregivers because they can find practical advice on the day-to-day hands-on care of the patient from those who have already done that and learned much. Your friend’s wife may really appreciate that aspect.