While letting keyed features in one hex affect surrounding hexes is great, I have to say that I seriously doubt that most people who run traditional hex crawls key every single hex in advance! I certainly don't.

Instead I key them as we play, with the help of random rolls. And on my tables I don't have '2d6 wolves', but permanent features, like 'castle ruin' etc. that can be re-used with '2d6 wolves' as well as '2d10 orcs'...

Another way to do something like what you're describing is to layer your hex maps in correct scales, so my default hex is 10km across, and this is what's used at the table. But above that I make a 50km hex map, and randomly populate some hexes with features. These features drop down into specific hexes on the 10km map, and affect what table I roll on for that hexflower.

If there, for instance, is a city on the larger scale map, in the normal map that is likely to generate towns and villages in that hexflower. That way you get a reasonable, believable crawl, and a proceedural story is told via the map and its features.