Had time for only a very quick test.
hope my math is right....
DH4
(from xdp file) MaxWeight (2352) & DryWeight (1636), difference is 716 lbs.
Two 230 lb bombs = 460 lbs
Therefore, with two crew, two 230 lb, and one 112 lb bombs, the engine should not produce enough thrust to takeoff (i.e. maximum takeoff weight).... and that didn't happen with stock WOFF PE.
Then I "fixed" the mass values and the result was as expected.
230 lb Mass fixed to "404.33"
112 lb Mass fixed to "350.80"
It's interesting to note that fuel was burning as it was trying to roll around the field, and the DH4 eventually had enough thrust to take off after 44% fuel was remaining.