That's what I'm doing. I'll probably have enough for the backpacks before this chapter ends, but last time it was mathematically impossible for me to get the next round complete on time so I knew getting JackJack wasn't going to happen. This time I'm just collecting. If I get enough for CR, great, but I'm not counting on it.
I have mixed feelings about this type of event. On the one hand, i can get characters I didn't get a chance to have because I wasn't playing for their events. On the other, I end up with one poor character from a collection who has no friends and no real storyline because the rest of the characters are there. They just end up taking up space. And because I am still early-ish in the storyline, I don't have any chance of getting the "goal" character. These are kind of a waste.