Put an in inline filter after the tank.After the heater use hose going to the reel that is okay with heat such as car heater hose.
We are not allowed to give advice on this subject for obvious reasons.
The L5 can be a bit of a numptie.In very low temps, when the gas pressure is low, when the tank is nearly empty, the numptie can become a complete idiot, as mentioned above.
Lots are very happy with them and i expect you will be.Forget the door thing.