Separate time scales for different (groups of) agents

hello all,
the “time_step” is a global parameter; since the “scheduler” executes for a user-defined number of steps [see function void bdm::Simulation::Simulate], this means that ALL existing agents in the simulation will “run” simultaneously!
therefore, i was wondering if anyone has ever thought of, or has implemented, something that would involve using a time scale (“time-step”) for some agents that is different to that of some other agents.
thanks in advance for your replies!