[Rich Biebel]

Buy a 20lb bottle with a dip tube
Buy 2 ball valves and braided steel lines and the correct fittings to connect to the large bottle and the 10 oz bottle
Go to you tube and watch a video or 2 on how to fill a bottle
I made up this setup and could fill a bottle very easily and quickly without using a scale
The parent bottle pressure is not high enough to over pressure the 10 oz bottle and quickly fills it. You can get many refills out of the big bottle.
I watched my pressure gauge even on the hottest day and the pressure never was high enough to blow the safety relief valve
I had 3 bottles and could change one in a couple minutes.
The better solution is a K&R on board air compressor
I gave my refill setup to my friend and when I needed to use an air shifter bought the K&R and there is no need for bottle refills....