Feasibility of custom implementation for SimulatorFunctionType do_md?

GROMACS version: 2024.1
GROMACS modification: Yes
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Hi, I am trying to do a feasibility study for implement a custom do_md(). So, I want to know is it possible to do so and if yes, how does the inputs and the simulation state work? I tried a dummy function instead of calling the do_md() but I don’t how the initialization, integration and the force calculation works.

P.S.: I know it is a very vast and vague question.
Thanks.