I have several recipes that I brew in rotation; some take 2 weeks to finish, some can be done in 7-10 days, and I've used kveik to get one grain to glass in 5 days. I try to schedule my brews so that there's always something in the kegerator. If the pipeline gets low, I'll brew one of the "fast" ones to pump it back up again.
For me, it's not a matter of "how fast can I get this in the keg"; it's mostly a matter of "oh crap we're running low, let's get something in there quick", while also brewing something else that can sit for a while longer. Life sometimes gets in the way of my brewing. As the great @Yooper said, when a beer is done, it's done; letting it sit another week or two ain't gonna get it "doner". I also don't like letting beer sit on the yeast too long, unless it's a lager that will benefit from it. Even then, if it's reached target gravity I'll usually keg it on day 7 or 8, and let it finish out in the keg with a little extra yeast to help it along. They mostly turn out great, and letting them finish in the keg opens up the ferment fridge for another brew. I'm lucky to have a kegerator that will hold six cornies so I can afford to do that.
For me, it's not a matter of "how fast can I get this in the keg"; it's mostly a matter of "oh crap we're running low, let's get something in there quick", while also brewing something else that can sit for a while longer. Life sometimes gets in the way of my brewing. As the great @Yooper said, when a beer is done, it's done; letting it sit another week or two ain't gonna get it "doner". I also don't like letting beer sit on the yeast too long, unless it's a lager that will benefit from it. Even then, if it's reached target gravity I'll usually keg it on day 7 or 8, and let it finish out in the keg with a little extra yeast to help it along. They mostly turn out great, and letting them finish in the keg opens up the ferment fridge for another brew. I'm lucky to have a kegerator that will hold six cornies so I can afford to do that.