Merit also means you start getting paid as soon as you punch in, not at your normal start time. So while progression TMs can punch in 10min early, merit TMs are supposed to be within 3 minutes, at least at my DC, since 10min would turn into 40min of OT.
The difference in expectation is that you know your job well and come up with ways to improve it. Make sure you keep track of everything you do “above and beyond” normal job duties, it’ll come in handy when you review yourself next year. Yes, you’ll have to review yourself.