Hi there and welcome!
I also use a propane torch and follow the
AMNPS directions with a slight variance.
I light the pellets for about 45-50 seconds with the torch (not on full blast lol).
I follow the directions to allow the pellets to burn with a flame for 10 minutes then blow out and go.
NOW, I have noticed that sometimes pellets do not want to burn for 10 minutes straight.
What I learned in this case is that I needed to microwave my pellets for 1min 15sec, stir and let set for 2 min, then microwave again for 1min 15 sec (don't do more than 2 rounds of microwaving AND the 2 min break is needed).
The microwave trick will usually then allow the pellets to burn with a flame for 10 minutes or really close to it.
This shows how the microwave zaps out the unseen/undetected moisture in the pellets.
So if you are having trouble with a maintaining a 10 minute flame you should have all the info you need to power through it... provided you don't live at some really high elevation. In that case the A-Maze-N tube version seems to be the preferred option.
Best of luck!