These are mounting plates for using ½" EMT pipe to make your prop more rigid and easier to install on your display. I recommend PETG or ABS for their thermal resistance since these will likely be outside. Here are my PETG settings

Print 2x Mount A and 2x Mount B

245 / 70

3 walls

40 mm/s print speed

8mm brim so PETG does not warp

50% fan starting at layer 4

Support settings!!

Normal

Everywhere

80 deg overhang angle

I think this is perfect because it gives you support at the trickiest spot at the top which is really the only place you need it.