I used to want to see higher yield. Now I have to say: I need to see what the potions can do as making the yield higher might make it too easy to get potions and force them to be nerfed.
So far it seems the essences are much more effective than the herbs alone (yellow crumb herb = 1 min of double learning; essence of yellow crumb, which takes 5 yellow crumb flowers = 10 min of double learning), so I suspect that the potions will be even more useful.
The yield might be just right when it comes to the growing times it takes to make essences and potions, at least if the buffs from potions are as big a boost over essences as essences are over herbs.
I imagine that housing changes won't happen now that we've got housing customization incoming. I'm still likely to go with a bog style house though, unless they release a style I like better.