"...and that the CFI has to work with you in areas that he/she sees you as being deficient.
"
This is not literally true. The BFR gives both the pilot and CFI a lot of leverage in the absence of requirements. If someone comes to me and says, "you know, I aint done a power on stall in 30 years... but what I am REALLY afraid of is soft field takeoffs in that 235HP Cessna RG", we can go out and do JUST that for an hour.
In practice, my "expectations of proficiency" so to speak are a lot more lax on the BFR than doing an insurance checkout for a renter.
Two extra comments on the BFR's, and I have done a BUNCH in the past six months: 1) when I meet with someone and the first thing outta their mouth is how many hours they have and all that they have done blah blah blah.. WATCH OUT. These guys have surprised me with the things they do to me in the airplane, and 2) the best BFR's I have conducted were with people (with 100 hours, 10,000 hours.. dont matter) who treated it like a ride that they could fail!!
just my two cents.