Can't co-witness with the Hi-Lux, it's not a true 1x. Co-witness is silly anyway (in my opinion) why would you want to clutter up your sight picture any more than you need to. The CMR has a great reticle, leave the flip-ups folded except when you pull off the scope.
I own a CMR which is how I know it isn't a true 1x, you only see a bury thumb or sight through it at 1x.