Appreciate if someone could tell me how long MMF can be at room temperature in a ziplock???

I've used mmf that was wrapped in saran wrap and then in a ziplock bag for up to two weeks for cakes. After that, I just use it for practice, even though when I knead it well, it's still nice and it tastes okay, but I'm always iffy about using it for a cake after that. I just make cakes for my family and friends though, not to sell.
Maybe someone has a definite answer.