It should be noted that the CFI PTS specifically requires demonstration of pilot proficiency at the commercial level in all the flight areas/tasks. However, the FAA's argument on this matter is that as the regulation is worded, you only get flight review credit for "a pilot proficiency check conducted by an examiner, an approved pilot check airman, or a U.S. Armed Force, for a pilot certificate, rating, or operating privilege..." Since a CFI practical test is not a test for a pilot certificate, rating, or operating privilege, it doesn't count for flight review credit. Thus, it has nothing to do with the content or manner of the CFI practical test, just the words in 61.56(d). The way to fix this is to get 61.56(d) reworded to include a CFI practical test, with the justification that on such a test you must demonstrate pilot proficiency at the commercial level in a representative set of areas/tasks. Perhaps it's time to petition the FAA IAW Part 11 of the FAR's.
It is also interesting to note that while renewal of a Flight Instructor certificate by any means listed in 61.197 (including FIRC, practical test, or activity) gives you credit for the ground portion of a flight review; the CFI must then still get someone to sign the flight portion after at least a one-hour flight.