My view is perhaps rather counterintuitive.
However, if I were asked to act as a 'conditioned mentor', and were adequately qualified, I think the prudent thing would be to decline so to take that role unless the 'mentoring condition' were removed.
I am entirely convinced that it is an excellent idea for a stalker, especially perhaps a beginner, to gain experience by going stalking with a sensible and more-experienced stalker. That, however, goes not require 'conditioned mentoring'.
I'm grateful to Orion for listing the objections to 'mentoring conditions', the raising of which might help in the removal of the condition.
If the FLD thinks the applicant shouldn't have a FAC as he can't be trusted in the field with a rifle on his own then he shouldn't be granted a FAC. Such an applicant needs more experience
before grant of the FAC (as suggested in the HO Guidance).
My approach would be to agree to act as a mentor as long as the condition were removed, and I think if more people of 'conditioned mentor'-level experience took that approach there might be less of this nonsensical 'conditioned mentoring' and a bit more issuing of FACs only to those who the Police thought were fit to behave sensibly with a rifle.
I am in no way suggesting that people who generously and selflessly act as 'conditioned mentors' are setting out to be either coppers' narks, or collaboraters with an unjustifiable and oppressively restrictive control measure thought up by the Police.
In effect, however, they are both those things; and as Mr. Chickenman points out, some of those who support 'conditioned mentoring' might indeed be basing such support other than on the welfare of novice stalkers.
The answer, dear Readers, as to how I would help a friend who had unjustifiably been saddled with a 'mentoring condition' is that I would use my persuasive charm to get that condition removed. If that didn't work, I'd have to reconsider my original position - but at least I'd have tried