That's fair enough, but it sounds like you've constrained yourselves and your code for the sake of a few enterprise customers, and now you've had to clear your

That's fair enough, but it sounds like you've constrained yourselves and your code for the sake of a few enterprise customers, and now you've had to clear your technical debt with a complete rewrite. Even if batbomb were right I would argue that any solution is better than supporting 2.4. The very minimum you would want is 2.5 at a stretch.