I didn't like the ones out there so I made my own. It was a bit of a learning curve but now I'm happy with how it came out. My main issue was flow. The hoses I got were too restrictive and the regulator really pulled the flame down when it cooled off. I ditched the regulator and just run a ball valve. I also discovered my fitting to the bottle was not a high flow, that got replaced. My next issue was the bottle freezing so I added a heating blanket.
In the beginning I could get a five foot flame. Once the temp dropped and the bottle cooled off, I was lucky to get a two inch flame.
Here's what it is now at 50% at about 27 degrees.
These are all the things that can cause low flames. All of them are restrictions except the bottle temp. I would start with removing the regulator and using the bottle knob to regulate it. This will show you if the issue is your regulator.