What are you even on about? I've been getting bonus stages almost every other run on average on the Phase 2 80 stam map and full cleared (except for the 100 gacha seed and 100 gold cards) yesterday (without using refills unless I was got distracted running manyu day maps). I get that the bonus stages are somewhat RNG, but your luck can't possibly be that bad. If it is, then you have my sincerest condolences.
Why would you random flip anyways? Paraphin linked the card table info in the OP so people can avoid the sucky cards and pick what they want to get.
edit: Oh. So you basically haven't been keeping up with the event and don't want to scramble at the last minute and want to blame Nutaku for your apathy. Got it; but this isn't really Nutaku's fault then.