We used to have 4 UY, but we sold one last year.
We now have
BWV (Oct)
SSR (Dec)
VCG&BLT (Jun).
We mostly use our points at the home resort at 11 months, so it works very well for us. In fact the contracts that confuse me the most are the two that are on the same UY. Sometimes I have to do a little clicking around to figure out which home resort points are which when planning to book a ressie at 11months.
If we had to combine points to make a reservation, it might be a little trickier, but that is where the once per year point transfer comes into play.
I don't think I would want to tackle 2 UYs for the same resort, but maybe the work around for this is to transfer all the points from one contract to the other each year. But, then you have to have a good record keeping system. I can see point transfers online from the same resort/same UY, but not if they are different.