Checks when steps get initialized

I recently experienced a case that step SN always failed, in the example it was caused by having no SN model which matches.
But instead of getting told about this at the beginning of the pop-syn, it run all through letting all systems entering the SN step fail there. Even more striking all systems which didn't get to this step evolved correctly, hence a quick check on a system, whether the run went well gave the wrong impression.

Hence, I'd suggest that we should add checks in the initialization of all steps to tell the user at this point if a step will always fail. I guess, this will be like the adding of the error and warning classes, that different people will need to do this for different steps.