It was a hidden feature in other Mobage Card games like RoB. When you turned in 5 tickets at the same time the 5th one had increased odds of being top tier. Because 5 is hard to get and new players don't save, they didn't flood the market.
Our premium box is 14 cards right now so, perhaps saving 14 might allow you to pick the box itself as option. The box use to be 10 which is why I was saving 10. It's unlikely that 14 will do anything since 10 did nothing and the half box has never become an available option but, I've already used at least 40 tickets so far (total not all at once) and I've gotten seven 4* and the rest split pretty evenly between 2* and 3*. The drop rate of well below 5% seems likely for valuable cards so I doubt I will get anything this year without help from a hidden booster or cash and I'm not going to spend cash.
*From Brave Packs so far I've only gotten six 3* out of somewhere over 2000 pulls.