I wouldn't put any water on board when towing that Outback even if its only around 6k dry.
Water sloshing around can make that TT feel unbalanced....in addition to not having your WDH setup just right. With a 1/2 ton you really need an additional sway control bar added>really helps.
Tundras are really the only other 1/2 tons I see towing relatively heavy TT's...nice that they have 4.10/4.30 gear set.
Airbags and or helper springs work to curb sway-IMO.
Last year when I picked up my 2018 Keystone Outback....the RV service tech forgot to drain the water tank?
My 14` F150 Boost pulled it fine...but I knew something felt different-lol
