When I researched the Fuji X100 series, I noticed a surprisingly number of self portraits of right-eye shooters looking through their rangefinder cameras with both eyes open.
Looks like an interesting self portrait, and users promote that it helps you connect with your subjects, but it just isn’t practical.
Unlike looking through a 50mm lens on a 35mm camera (the view through the viewfinder looks identical to the view through your eyes), the focal length on an X100 camera is wider at 35mm (35mm equiv). That means you don’t get this seamless blend like both eyes seeing the same thing. It’s like looking through one half of someone else’s strong eyeglasses.
This makes composing and watching for expressions and details a great deal more challenging (and gave me a headache).
If this works for you, great, but, for me, it takes me too much concentration away from photography.
And be warned, this may be a What-You-Think-You-Look-Like vs What-You-Actually-Look-Like situation when you aren’t get your portrait taken.
(I’m a left-eye shooter anyway which means I don’t have to squint my right eye, but on a rangefinder, it means permanent nose-smudge.)
Good luck and happy shooting!