There are cases where you do need a casa approval to pass on theory but usually only if you're the person assessing or examining the candidate.
This applies to internal PIFRR exams and some AME exams.
As far as I understand (not fully researched) there is no requirements of the theory provider if the candidate will be required to sit a "cyber exam".
Since the BAK is internal there may be requirements to have the examination approved.
I think the main thing is do you think you're capable or adequately experienced/qualified to be providing the theory?