I hear you but in your scenario you could also compare it to the family of 5 that kids all clear the height requirement. One child is going to ride alone and not with either parent, sometimes out of reach to even talk. It is not up to Disney to make sure every parent rides with every kid.
I am not saying there shouldn't be rider swap, it just needs to be set up in a way that its not being "overused" and putting it digital stops the "abuse" ... much like what was happening with the old GAC.
Maybe it will be similar to the
DAS (new version of GAC). It is now digital. At Guest Relations IF YOU ARE APPROVED all members in your party scan their MB. If there are 10 of you, fine all 10 are scanned. BUT the rules are only the DAS holder and 5 others can ride with the DAS. When you get your return time, you tell them which 5 are going with DAS holder. They check them off your list on their device so their MB works when they return. For RS maybe what it will just mean is that 2 or 3 people (website rule or paper pass rule) that were present and scanned will be activated to use the return pass. Once those people scan to use the pass then the system would not allow anyone else.
Everyone was upset with new DAS but it works great. I think this will be the same. We don't know, but if folks are restricted from doubling their FP+ then they will just have to do some more planning .... or do what I do, use my FP+ for something my kid can do. In the end you can roll FP+ so many times every child should can do everything they want to do.