Looking for Input on SimBrief Weight Confusion

Since I have adopted BATC, I am now fully reliant on SimBrief for ATC and I’m using it more than I may have in the past.

I am primarily a GA pilot, but I do like to fly vintage airliners and the occasional 737NG (I’m missing these in 2024…).

Okay, I have noted some confusion with calculated weight in SimBrief vs. what I see when I configure an aircraft in-sim.

Example, just now I am trying to setup a flight in the Just Flight F28-4000. I enter my basic info into SimBrief and the calculated weights don’t correlate with what I see in the aircraft’s EFB when I enter fuel, passengers and cargo. I end up much heavier in the sim.

This isn’t the only aircraft that I’ve encountered this with. I’m at the stage where I want to understand what is happening here, so I can correct it and have the weights more or less correlate by a reasonable margin of error.

So, for science I set the passengers to 1 and the cargo to 0. On the flight I setup it’s calling for 8794 lbs. of fuel. (Sorry, I live in that backward country that seems to think the metric system is the work of the devil. Sigh)

Okay, I enter the fuel and passenger into the F28 and get it loaded.

SimBrief says my OEW is 32825 and the EFB says 39505
SimBrief says my EZFW is 32825 and the EFB says 39675
SimBrief says ETOW is 47019 and the EFB says gross weight is 48469 – I’m not going to burn ~1450 lbs. of fuel on my way to the runway, right?

I’ve checked that SimBrief’s profile for the passenger weight is the same as the EFB in the F28 and they are both 170 lbs.

I note the “Empty Weight” in the EFB is 39505, yet SimBrief has 38825 as does Just Flight’s documentation. This is a difference of 680 lbs., which doesn’t account for the 1450 I mentioned prior. If this is crew and stores, then where is that accounted for in SimBrief?

Anyhow, help a brother out here. What gives?