Start from the initial value of the unsteady state

Is there any way for me to simulate from the initial value of the unsteady state?Better to give an example.

Please elaborate. What do you mean with

?

Because my initial value module will report an error once it is a non-steady value, I want to be able to simulate from any initial value without considering the steady-state problem.

You can study transitions to a steady state. But you always need to have a steady state and be able to compute it.