The large sides and trailer won't make it more pivotal.
The reason Simon started using a thruster set up was for more pivot in the first place.
Put in the K2.1s.
If the tail is letting go simply use a larger centre.
You can fine tune the amount of hold/pivot by then adjusting with the use of the rear fin with different size/rake to your tastes.
Come back and tell me if I'm wrong.