The F14 Max Trap Weight kept increasing as the aircraft morphed into medium attack. I don't know where it ended up, but increased from 51,800 to 54,000 when I left.
It is quite simple. You take the difference between max trap and existing weight, and that is your max fuel to bring back aboard. Ordnance expenditure is simple to calculate as well, missiles are 1000, 500 and 200 pounds respectively, with around 500 pounds for gun ammo and 250 each for external tanks. Calculate max fuel for trap with all existing ordnance before takeoff, and add fuel using the above weights for any expended ordnance. Easy peasy.
Dump rate was around 1500 ppm, and you wanted the the dump shut off early so as to not stream residual fuel over the ship as you entered the break.