Yes, but I am not sure that this would, in fact, be feasible from a legal standpoint. I believe the prerogative is protected constitutionally and implies discretion. That discretion cannot be touched, and legislation must not prejudicially affect it.
There is a second point as well. You talked about the legislation on fixed date elections, but I am sure you noted that the principle of ministerial responsibility is nevertheless protected and respected in that legislation. In my opinion, it is a poor example under the circumstances. The principle under discussion here is left intact—in other words, the primary principle, that being ministerial responsibility. If I apply the same argument to prorogation, I would say that you would also have to respect the principle of prorogation in any bill that attempted to set parameters around it. This goes back to what I said earlier: the legislation must not be so broad as to alter the prorogation power or place excessive limits on that power.
Finally, you referred to the establishment of a possible constitutional convention. The fact remains, however, that even if a constitutional convention were to be established whereby the government had to show self-discipline in its use of prorogation, if the government were to decide one day that it was no longer going to show that kind of self-discipline, in my view, the Constitution would trump that constitutional convention. And, since I believe the prorogation power enjoys implicit constitutional protection, once again, that protection would trump the constitutional convention.