Hi tozz, welcome to the forum.
Based on your picture of the baro location that is fine, although my preference would be to mount it at least 1' from the elbow or the 4" to 6" adapter. I would also say by the amount your baro is open you are wasting heat out the stack. I adjust mine to give me .03 to .04 with the baro shut. Just remember as soon as the flap on the baro is open you are causing room air to mix with the flue gases to achieve the correct draft. IMO, not only is that pulling hot room air out of the house, but it is also causing more heat to go up the chimney than needed.
On my stove I achieve 600* stove temps while the stack at the power vent entrance is only 84* , the power vent inside at the exhaust is 60* on a cold day like today (also using a laser). One thing you need to be aware of, if your laser is not adjustable for emissivity, there can be an error based on the surface you are reading. The black stove pipe Vs the galvanized need different emissivity settings (high on the black and med or low on the silver depending on reflectivity).
To answer your concern, I feel you are safe running it as you are, the draft measurement is in the right spot, so really doesn't matter where the baro is. You can calibrate the weight location for your current set up by moving the weight and adjusting the rheostat to get the baro to just open at your desired setting.
With respect to measuring static pressure (the draft in the stove) over the fire you need to access the combustion area. My Harman has a small plug in the front of the stove over the ash door, I remove the plug and insert the manometer probe there to get this data. In my Alaska stoves I had to drill a hole and tap it for a 1/8 pipe plug. You can ask Jerry at LL about your stove to see if it already has a location to check this, if not using the same method I did on the Alaskas will work. Just remember to put a dab of never seize on the pipe threads.
Enjoy the science project!