What if I made the statutes part of the bill
Well that would definitely be better than nothing (I generally think that if statutes are needed for an orglaw amendment to be functional, best practice is to include these in the bill instead of adding them later.)
but I would still urge you to consider at least putting the starting date (relative to the convocation being called) in the orglaw. For comparison, exact election dates are in there as well. And this is really important because it's going to have a large effect on the composition of the convocation. Do we really want a Ziu majority to be able to alter this during the same term as the convocation itself? This seems like exactly the kind of thing to anchor in the constitution.