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.)
Money getting involved would indeed simplify the question.
Here no money is changing hand, so coming up with an angle that's motivating enough for the devs is IMHO the only option. Either bring up an aspect they're not considering that changes the equation for them, or come up with a solution that isn't plaggued by the issues they are afraid to deal with.
That's where I see listening to the devs and caring about their issues to be the only path forward, short of contributing as a dev oneself..