What do you mean 3 day wait? I haven't done the photo connect in a couple of years but I never had a wait period. Bought it, activated and could see the pics on the app almost instantly.
OP is talking about Disney's Memory Maker and confuses things even for the Disney part
So let's try to clear things up :
At disney's, there are 2 prices for Memory Maker
- Discounted : you need to buy the Memory Maker at least 3 days in advance to get the discounted price. If you buy at the discounted rate, once in the parks, your first 3 days of photos will not be available.
- Full price : can be purchased anytime during the stay, or even after the stay, as long as pictures have not expired (they do 45 days after being taken)
At Universal's
- Presale : you can purchase a voucher, whenever you want, they don't expire (policies may change so double check before buying). You need to print the email confirmation, and once at Universal, visit a Photo store to redeem the voucher and get your StarCard, lanyard and holder. Register that card on your myuniversalpictures account, and then be able to see the pictures in app or on the web.
- full price : at the photo store directly
this can also be purchased as part of a vacations package.
link for Universal pictures presale :
https://presale.amazingpictures.com/UniversalFlorida.aspx