I'd definitely avoid the DB with 25s, yes (good instinct, you). He mentioned in the video, and I'm pretty sure he said it would take 28s without issue (and maybe/possibly 30s?). I'm pretty sure it was 28.
I'll try to swing back to the vid later, then come to report accurately.
The housing is for 21700, with sleeves for 18650, and people are requesting sleeves for 20700 too. I'm not sure where that last part sits, because I've not been locked in.
It's a big'n (IMO), that's for sure.
Release could be in the next few weeks (he said about a month, back on 5-Jan).