In the last photo I have a BP case on the left, which doesn’t have the additional step on the rehaut(?), so the gen crystal that I cannibalized from that build sat flush when it was installed over there. My understanding is that the step is gen spec, and that’s why mods to the hytrel gasket were needed to fit a gen crystal. But for some reason… the gen crystal was just normally fitted to the BP case so I’m extra confused.
First of all, a hytrel ring is a bezel gasket that is used in rotating bezels that have ceramic inserts. They are what locks the bezel under the crystal retaining ring lip, and facilitates rotation by providing a slippery medium that has enough resistance to stay put absent external force.
The 16570 does not have a hytrel ring nor a crystal retaining ring. The 16570 bezel acts as the crystal retaining ring, like the bezel does on a Datejust or a Daytona. The gasket all these models use is a crystal gasket.
IDK that I've ever seen someone try to convert a Noob 16710 into a 16570, usually it's the other way around. So there may need to be some adjustment (machining) made to the stairstep case protrusion on the Noob 16710. You can see from your added pic next to the BP 16570 case why your crystal sits so high on the Noob 16710. The first things I would check on the Noob are:
Where on the Noob stairstep protrusion does a gen-spec crystal gasket fit?
Where on the Noob stairstep protrusion does the gen bezel with a gen-spec thickness crystal gasket sit?
Is what you are trying to do even possible with respect to adjacent lateral spacing tolerances among the three elements? If a gen-spec crystal gasket fits snugly on the upper step, what's going to hold the bezel in place? Normally friction from the gasket holds it in place, but that friction would come from a gasket sitting flush to case like it would on the BP case. If the gen bezel fits snugly to the lower step, AND snugly to the gasket at the upper step, it's possible you could use a much shorter height gasket (2.1mm, or custom shave one to the perfect height) and a thinner crystal and you could use the Noob case as is. But you need to closely examine the lateral fit of all the parts before deciding your next step.
