It shouldn't be too hard to work around that by either using dev tools to force the installation or by simply modifying the app to bump the required version number. It sucks that installing unmaintained apps is going to be more of a pain, but it's far from impossible. Android's internal backwards compatibility for this stuff is quite good.
I had a feeling you'd say that. It's really not on the same level as all, but I think that's more about me than the keyboard itself, as I'm just used to tapping in a vague area rather than have to focus on being more precise.