I don’t see any reason it couldn’t be supported for a set of formats with reasonable encoding/decoding settings, and provide some error message for other formats if a user attempts to step back, e.g. reverse frame stepping unavailable for current video due to format/encoding/decoding settings.
- the devs expressed in no uncertain terms that they don't want to do it (the first answer is just perfect)
- every third comment is about "we know you don't want to do it, but as users why should we care ?"
Well, if you don't care about the devs, on what base are you asking them to care about your specific problem ?
Caring about the user's requirements is part of the dev's job description. Caring about the dev's... anything is not in the user's job description. (one advantage commercial software has: it really does help when there's an interface between the dev and the user in the form of customer support. or a commercial incentive to actually work on what the user wants.)
For OSS project, it's better to assume that the user persona for the software is the devs or the maintainers. The dev-user relationship you expect is actually the vendor-client in commercial software.