Set up on the Reflex is pretty uninvolved in my book, largely because they have plates with holes, not slots, for positioning of the Toe loop and the heel release.
You look at your shell to get the number, then you put the toe loop and the heel release on the plate, torque the screws down. Then you have the binding shell itself, which of course you make sure is assembled, and importantly, make sure the liner and shell are comfortable, thermoformable liners are nice if you have feet like mine - stradas have em too.
I thermoform my own liners, but I have infared ovens at work.
There is a published number for the heel ledge height, but I don't think this is even really an adjustment on Reflex boots. Maybe it used to be, but I think now its just worth a quick check with your caliper.
Then I would look at the chart for a recommended release number, it is based on weight primarily. Put it to that number, then do some releases of the boot before you ski it, make sure on good hard tugs you don't feel like you're breaking your foot, the boot, or your ankle.
And that's where you start skiing, thing is you also want to make sure you aren't so light on the number that you prerelease, or so heavy that you sprain your ankle. No such thing as a miracle binding. And you need to adjust all your buckle tensions, and mark them so you use the same everytime. Otherwise somedays you have edge control and somedays you do not.