+1 to having sour beer around for blending. I read that, even in Cantillon, they have barrels that are so acidic they're "only good for shining the copper".
Nateo - are you worried about over-carb'ing / bottle bombs with such a young, non-soured portion? Do you just drink them quickly enough to avoid this issue?
I still wait for gravity to stabilize after blending. On the latest Red that I was talking about, that meant blending, then sitting for 3 months. Gravity was stable for the last 2 months, so I bottled. I'm using Champagne bottles to avoid bottle bombs. They might carb up more, but I estimated a "worst case" Brett overattenuation figure using Kai's carbonation spreadsheet, and adjusted my priming amount to account for that, so it's not likely they'd "over carb."
I'm not really sure what the shortest turn-around time is, but I'd guess it's around 1 month. I haven't tried that yet, so do so at your own risk. Still, 3 months for a Red is a lot faster than 1-3 years.