the main thing about this thread is to stop refilling 1 pound disposable tanks. the op said they were not available (recalled for 2 brass fill valves became loose because flame king forgot to use loc-tight on the threads and no one was injured) when he built his refill kit, but that he wanted the flame king system. it is now available to all of us.
here's a good way to look at some math on recovering your costs that last for 12 years or more. they are certified for 12 years.
i use up to 4 1 pound tanks in a long day. if you pay 4$ for those tanks you have over 16$ into them. the flame king tanks can be bought for 12$ at menards with rebate. that means for every day i fish it would cost me the price of one flame king tank and be able to fill it about 8 times or more with the 4$ left over from the disposable cans cost.
and the disposable tanks are a hazmat issue when disposing them.
the gas in the disposable tank would cost about 50 cents tops, so you spent 16$ to burn 2$ worth of gas and wasted the remaining 14$ that could buy the flame king bottle. times how ever many days/weeks/months/years you go.
we have heard stories where the disposable 1 pound tank safety valve was venting inside a moving vehicle and the driver was smoking. the 1 pound disposable was over filled and after being in the heated vehicle it vented gas inside of it.
i have had the fill valves leak on them after refilling.
remember you are filling these outside and after the season is over they are still full and then the heat of summer gets to them or the heat of your vehicle or the heat in your shelter and you may have a problem if over filled or a fill valve or safety valve become faulty like has happened to myself.
Just use a 5# tank and a hose and be done with it. Local propane dealer can refill it and you won't have to dispose of those green bombs.
if it works for you that's great. not reusing the disposable tanks is huge. the reason you say use a larger tank is because it is certified refillable for so many years.
many of us are now using the flame king system that is certified for refilling.
https://www.iceshanty.com/ice_fishing/index.php?topic=361359.0besides the safety and legal issues with refilling disposable tanks, here is why i am using certified refillable1 pound tanks;
my lpg lantern takes 1 pound tanks only. the tank is it's base/stand.
my mr heater little buddy takes 1 pound tank only. the tank is it's base/stand.
my micro cooker takes 1 pound tank only. the tank is it's base/stand.
my torch uses 1 pound tanks.
my grills side burner uses 1 pound tanks.
the 1 pound tanks are too convenient to stop using them and necessary for me.
plus i can fill 1 pound certified tanks when i want them filled at my convenience. i work with 2 20 pound tanks so i always have lpg on the ready. i also like the base of the flame king tanks. it is just like all the other refillable lpg tanks.