It's probably worth noting that G3 and Robin are boosted day 2, though it's a single boost. Both can be pretty game changing RR units.
Yeah, I'm just assuming more people are missing Doffy 1+3 units than Doffy 2 + Early RRs. Any time you're gunning for a specific unit you go for their boost, though I'd probably wait for a double boost if possible.
Day 2 is also risky since the double boosted units (Giolla and Lion Song) are pretty poor even if you don't have them yet.