Note: In part 61, the 2 year/200 hour requirement applies ONLY to the actual sign-off for the check-ride. Any CFI can do prep work (ground and flying) with an initial CFI applicant to get them to proficiency. At that point a 2-year CFI must take over and do flight/ground as necessary to satisfy himself the the applicant is ready...this can be done in one day with one flight and a few hours of ground as checkride prep (assuming the 2-year trusts the other CFI).

This is legal because there is no specific amount of training required for a CFI applicant, just to proficiency.

I agree that in 141 you can get around the 2-year requirement, but the CFI course must be conducted fully under 141, which is usually too cumbersome in my opinion.