@DavesNotHere talked about making their own JA foliar using KNF OHN tek on fresh jasmine flowers or dried ones rehydrated with flat cheap beer, maybe @BeagleZ or @Wuachuma might be able to comment on that approach, since one of your questions was how to DIY it organically.
My thought on it is that the plant generates endogenous jasmonic acids as a stress response, especially to leaf or stem damage, so topping, aggressive supercropping and other high-stress training techniques along with Day 1-21-42 defoliation in flower are probably generating plenty IMO