It's also depends on what makes sense. Like if you have nothing to go off of then you can't post. Besides, if it's an OP then it's going to be chaotic. Oh and wb !
Generally, I've been mostly playing off of post order for combat only. If there are more than three in a thread, and no combat is initiated, then I don't expect anyone to keep post order. Especially since I sometimes don't post for a day or two, because of work.