A commit that was "co-authored-by" 6+ people and has three thousand lines of code: this is a total wreck of a development workflow. This feature should have been implemented with a series of about 20 patches. Awful.
You are being downvoted, but you are entirely correct. This is also explicitly not allowed in FFmpeg, but this was pushed after many months, with no heads up on the list, no final review sign off, and with some developers expressing (and continuing to express) reservations about its quality on the list and IRC.
The biggest thing missing right now is NACK support, and one of the authors has said they intend to do this (along with fixing old OpenSSL version support, and supporting other libraries). Until that is done, it isn't really "prod ready", so to speak.
For some context, there has been a history of half-supported things being pushed to FFmpeg by companies or people who just need some subset of $thing, in the past, and vendors using that to sell their products with "FFmpeg isn't good enough" marketing, while the feature is either brought up to standard, or in some cases, removed, as the original authors vanish, so it's perhaps a touchy subject for us :) (and why my post was perhaps unnecessarily grumpy).
As for the git / premature push stuff, I strongly believe it is a knock-on effect of mailing list based development - the team working on this support did it elsewhere, and had a designated person send it to the list, meaning every bit of communication is garbled. But that is a whole different can of worms :D.
Perhaps "common and technically works" would be a better way to put that (similarly for rebase). I suspect people would stop squashing if git gained the ability to tag groups of commits with topics in either a nested or overlapping manner.