Phone-based Mixed reality Headset for UE developer

Asking for information/vision from experience developer. which Phone-based Mixed reality Headset is suitable for developing MR Content by using unreal

  1. Mira Prism (Single reflection)

2. HoloKit (Double reflection) (Also seebright…)

do you have other type of MR-Headset (Phone based) more than this? for me Mira Prism is looking good, light weight. since it use only single reflection I think the image quality may better than HoloKit but may need to flip the output image.

P.S. Sorry for my English.

Thank you.