I have never used propane, but used a natural gas/O2 torch when working in a fab shop. They had the propane piped all over, moved an O2 tank around on a cart and just plugged in. Far superior cutting than Acetelene. Even manual cuts were clean and no slag to clean off. Did not even have to hit with a grinder even on a bevel cut. I think I will check on getting the tips and set my cart up for both gases if it works. I do a lot of OA welding on thin stuff or if I want to do a one pass job like that thread on the propane tank/roller conversion. Also do brazing both bronze and silver and soldering of copper; so, propane works for that also. Acetelene is getting priced out of sight with the low volume demand, due to these other new proceses on the market. Used MAPP gas once but was unimpressed, it has gone away also now, I guess.
Back in the 90s a company came out with a torch system using gasoline and O2. The demonstrations were awsome to watch. No slag and no heat below the cut. They had a lady put her bare hand 12" below the cut and all she got was some fine black ash. Very claen cuts also. It never caught on or was not accepted by the safety police so do not see anymore. Always wanted to try it but never worked any where where it became a tool.
I am still a O/A fan as I am better at it than arc. Grew up on O/A welding of steel piping systems up to 6".
Time marches on!!
Ron