For example, imagine a very old old foreigner requiring a Zimmer to walk, with a Chinese spouse, being forced to take snnual medicals. Even if he (or she) failed them, it's ok for him (or her) to remain in China.

Do you think that they really want to keep these medicals in place to screen for sexually transmitted diseases? if so it's a bit of a contradiction that the likes of SB and co can spend holidays in China for the sole purpose eating squid and spaghetti on toast in between visiting whore houses; no medical required; whereas, married and living in China westerners, pose comparatively smaller risks at attracting contagious diseases than said holidaymaker. No disrespect meant to SB.