As I said.
My CRI skill test included "sorting out", a nominal pilot who had failed reval by test on circuits and PFL. Either I was trained to do that, and passed the skill test, or I didn't.
Last week I was converting a rusty PPL onto an elderly taildragger that I have plenty of hours on. I could have got an FI with half my hours on type and tailwheel to do it, but the logic escapes me why?
Yes a CRI can do less than an FI. But we have a licence and rating obtained by passing a skill test, are required to revalidate them as per the rules, and if we do: deserve to be judged as "an instructor" like any other so long as we stick within the privileges of our rating.
But as we are given quite a lot of privileges, with significant overlap to FI privileges, similar revalidation requirements to an FI seems appropriate to me.
G