I'm afraid the argument about off-label use won't be very compelling to doctors, because of how the FDA works. (I've seen doctors respond to this argument for other drugs.)
The FDA only evaluates a drug for a given purpose when a company submits an application to do so, along with the proper data and so on. Once a drug is authorised, it is legal (in most cases) to use it for anything. (This doesn't mean a doctor can't get in trouble for not practising within the accepted standard of care if something goes wrong, or that Medicare/insurance would pay.) The manufacturer only submits it for authorisation for further uses if it would somehow benefit it to do so--usually because they want to be able to market it that way. It's legal for doctors to use a drug off label, but it is not legal to market it for unauthorized purposes. Therefore, Novo Nordisk submitted an application for semaglutide as Wegovy, so they could market it as a weight loss medication. But it's perfectly legal for doctors to prescribe the Ozempic version even though the intention is weight loss. Leuprolide is no longer under patent, so there's no incentive to submit it for new authorisation. A company would be undertaking the financial burden of approval with no guarantee that they would get the profit afterwards.
Many commonly used drugs never received formal FDA approval for those uses, even if there is clinical data supporting their use, because it is expensive to do. So Lupron is also commonly used for IVF, but it does not have FDA approval for that indication. It is also used in the treatment of precocious puberty.