My shorter FB2200 Weekend Warrior was like yours in regards to tongue weight change due to the axles pushed farther back on the frame. For a long time, I couldn't figure out why travel trailers could pivot tighter than me even though they were longer until I looked closer at the wheelbase length to the tongue and realized most TT's have their axles at mid point and while TH's have them about 2/3 to 3/4 of the length back. My TW was not nearly as heavy as yours even though we had the same tank capacities because my underside was almost filled front to back with waste, fresh and fuel tanks putting more over or behind the axle than yours.