Question about complex dynamics with TRT and force external

Hello everyone;

I am simulating the flow in a microchannel with variable dynamics. In this case, for my study the dynamics is a relaxation parameter dependent on the local density in each cell. The simulation works in the following cases (with D2Q9 and D3Q27 models), and I validated my result with the paper Microchannel wth LBM.

1> where the flow is induced by an external force, with periodic boundary conditions in the direction of the flow.
2> where the flow is induced by a pressure difference (between the inlet and the outlet), with non-periodic boundary conditions in the flow direction.

But I had a limitation of small Knudsen numbers at the outlet (< 2.43e-1). This limitation can be extended with the TRT model Microscale withTRT LBM. I have two questions.

1> How can I use the TRT model with an external force on PaLaBoS?
2> To include a TRT class with an external force at my variable dynamic class, Is there a problem that in PaLaBoS the class trtdynamics.hh does not have the option of TRT with external force?

Thanks for your collaboration.