The high pressure stove puts out probably twice the heat of the low pressure.
I gave up after years of attempting to get this to work, including working with my LP/welding supplier. It did not seem worth the effort to me as the stove is non-adaptable to low pressure hence the trailer needs to be modified.
To get it to work you need the gas system pictured above and plumbing to the stove mounting point (unless you want to get out and trip over a hose every time). You'll recall Coleman/Fleetwood ran pipe to the outside stove location with a capped outlet on the frame under it.
You'll need a "high pressure" regulator between the cylinders and your existing two stage regulator with a Tee connector in between the two regulators. The "high pressure" regulator is the same as a gas grill regulator according to the LP shop.
Cylinder --> HP reg --> Tee --> 2-stage reg --> Trailer
......................................\
.......................................\
........................................High pressure stove
Low pressure regulator can't handle tank pressure so it needs a high pressure first stage. Separate high and low pressure regulators do not meet "Code." Hence the appearance of the two stage regulators combining both.
Two high pressure regulators in series would be redundant if you didn't need the high pressure tapped off between them.
LP pressure INSIDE the camper (or dwelling)
must be low pressure. High pressure to your furnace, stove, or other LP appliance will cause a massive flame and is highly dangerous.
-- Chuck