Every time you start the develop branch it displays a huge message saying
"Version 0.300 is almost out!" (with a description of how stable releases on master branch are the current objective) and it's been displaying that message for 3 years. There is a rolling branch, but the release branch isn't rolling. Spacemacs is usable but the project is calcifying, I wouldn't recommend anyone hitch their cart to it.
Like, I'm jumping ship as I write this. My job for the next few days is converting my config to Doom.