I just fill it. I don't add anything anymore. (except yami ring-free on each fill up which I find helps a lot) Yami dealer said stabl or any other non yami product in the fuel will just allow them to blame that on any malfunction and void any warranty service when ever they can. They have done this before he said...blame a 3rd party product and not pick up the tab... So don't add add anything except their product to be on the safe side. They even pulled my racor filter out and replaced it with a yami filter (which I think is not quite as good personally as you can't see what is in the bottom...no clear bottom, but they are both 10 micron filters) I end up changing the cartridge every 50 hours just so I don't have a worry about it and keep a spare on board.
As for full vs empty....I tried them both with and without additives. I prefer it full as I think there will be less condensation over the seasons and I like starting the year off without having to fill the damn thing up
Also I think if you are only storing it for a few months it really doesn't matter much, if you plan on storing fuel for 6+ months maybe it will help to use an additive. Why risk loosing the warranty over adding something that may or may not work. Also I STILL don't understand the theory behind the additives. If you look at the contents it s mostly alcohol. When there was no ethanol in gas I can see that adding some alcohol will absorb any water in the fuel but since the fuel now has 10% ethanol in it (which is basically alcohol) that will absorb water. I don't see what adding more alcohol to the fuel will do...except maybe give you a warm fuzzy feeling that you are doing something to the gas.