I wish one of my instructors had mentioned this issue during my training. Not one ever did.
I think you can become a club instructor after 300 hrs, passing the CPL exams (but not the flying side) and doing the FI course? Someone will no doubt put me straight on that but it's not surprising that some instructors don't know. Apart from having the CPL exams under their belt there's no reason they should know more than I do and I know Jack. (In fact someone asked me at the club the other day if I fancied instructing, I'd like to learn how to fly first!)