@justip They are very handy, use mine all the time. My only advice is to prevent stickiness (I over flour the little dough ball like I do with bread) but the parchment paper is more traditional. Also place the little dough ball closer to the hinge as it gets pressed outward from there. Sounds obvious but it does help to get those sweet perfect round tortillas that impress.
As mentioned arepas are more hand formed. My sister is an arepa wizard (gluten allergy) and won’t hear of machine pressing.