Is it possible to be cis and maverique?
yup. although no one, at the moment, is assigned maverique at birth, maveriques have the right to have any gender modality they want.
non-binary identities are conceptually trans. with time, language evolves, things that overlapped each other can be independent due to populational use.
it's subjective and relativizational. for me, it's valid. also maveriques can be midbinary if they are multigender, for example. you don't need to be fully abinary to be maverique.
philosophically speaking, someday this gender essentialism will not be this much enforced upon other people. until then, we will show the world how complex and ample gender can be individually and collectively.