One of the things that concerns me is that word .... "wishes".
I've never been entirely clear where the final donation decision (*), short of a court case, actually lies :-
1) The deceased, according to opt-in or opt-out, or
2) The family, hopefully taking those "wishes" into account, or
3) Doctors, hopefully taking both 1) & 2) into account.
It strikes as a bit like making a will .... the will itself is legally binding and executors MUST follow instructions, subject only to a successful court challenge. But the "funeral wishes" bit you can optionally add to the end is exactly that ... your wishes. But next of kin don't have to honour them.
And me, having spent many years trying to distinguish (in either legal or political contexts) between what someone appears to have said/promised, and what they can be held to, and if necessary compelled to do, am concerned that the whole thing is a con.
Which is why registering "wishes", or preferences, or what you "want" makes me nervous.
Maybe I'm just being overly cynical, but .....
(*) IIRC, two doctors can override either registered wishes, or family wishes. Of course, it would be extremely controversial if them actually doing so became public knowledge. But where, legally, does the. final decision rest? Anybody know for certain?