I had all-pros also. I never really towed with mine. I did haul a couple loads of almond wood in the back, and they held an arch after some heavy loads. I took the bottom leaf out to level the ride hieght out alittle. I would leave that in if your towing though.
Aig bags or spring helpers would help, but De-arched spring are a common problem on tacomas. too much axle wrap ecspecially with lift blocks on the stock springs.
