I am what is sometimes called a "perpetual tourist", I simply exit CR every 90 days and return with another 90 day visa. Yesterday that ended, at least for now, when I was given a 30 day visa; no appeal, the discretion of the "interviewer" as to whether the visa is for 30, 60, or 90 days.
I know others to whom this has happened, but a rude first for me.
Of what use is power if it cannot be abused?
No real reason for not having done the residency thing - just the hassle.
If one has many pages of CR entrance/exit stamps, have a back up plan if only 30 days is given.
Bill