Would it be possible for an EMR software vendor to ship both a "canonical" client interface that meets all the specs/requirements; and then a separate, secondary client interface, for the same backend, which isn't included in the "package" of EMR software sold to the clinic/hospital/etc., but rather is instead a "bottom-up adoption" play, with download links to it being passed around under-the-table between doctors?
If there's any potential for doctors being liable for such-and-such if they were found to not be "using" the primary client, then said secondary interface could be implemented as macro+screen-scraping software, that operates the primary client-interface underneath—much like Mint used to do before banks supported OFX export. Then just get it classified as accessibility software, like a screen reader, and let those doctors claim a need for it :)