I would have felt funny about being compensated, and I think that type of element would cause more problems with the decision making process for the families.
add $$ into the picture and then it isn’t about trying to figure out what the patient would have wanted -
You can donate any money to a charity if you wish... obviously in the case of a minor the parents or guardian would be in control of any decision... as you have a cardiac surgeon in the family I’m going to assume that you have no money problems of consequence... My father died in the last year leaving my mother on a poor financial footing despite a pension (cut in half at his death) and SS and a small insurance policy,, he was a success , a salesman for IBM who made more than quota in most years (beginning in the glory years of the early 1960’s) but was unable to save due to medical bills related to my younger sister (20% of insane and inflated medical surgical bills are enough to destroy any savings), I don’t know what organs (if any) of his were used to treat others ,, I know he was an organ donor, it would have been nice to let his gift(s) assist my mother. I don’t have all the answers but it appears that in 10-20 years we will be able to salvage failing organs with adult stem cell treatments... I can see very clearly your ethical concerns when it comes to end-of-life donations ,,, I would like to see the rules discarded for blood donations and other living donor donations.