You can, it just depends on queue lengths and how long until your digital slot is ready.
Otherwise, I completely agree. Sure, if the theme park attracts mass crowds on a daily basis, who have a little money, and the park isnt particularly full of attractions, this would be fine. However thorpe has (I believe, may be wrong) 30+ attractions.This means that, unless the day is full to near its full capacity, there will always be one ride with short queues. I'm not sure if it will work. Maybe it could be temporary, and they only have it on particularly busy days.