I have refilled the cylinders for use with a little buddy in my shop and home. Refilling the cylinders seems to work better with Coleman units for me. I have gotten a few of the Worthington cylinders and find they leak frequently. Coleman cylinders have usually refiled well with no leakage. I get about 15 fillings off a 20 lb tank before it gets so low that it only about half fills a tank. I have a rack that holds the 20 lb tank tilted at about 45 degrees from upside down, so I get liquid propane movement instead of gas.
Not suggesting anyone else do it this way, but I have had no issues in over 10 years this way, I am refilling outside and I allow at least a half hour for transfer.