Shower Waterproofing

Ok so when I wake up at 3AM I have some crazy thoughts and this might have been one of them, but I'd like some feedback on it. Sorry I think it's going to be a long one.

I'm using Kerdi curbs for my shower. I'm going to put a layer of hardie backer on it for more beef and the shower glass installers want me to put wood in the hollow areas so their screws have something to bite into. That's the problem. They are going to use screws with silicone. That's what they do, they won't even think about anything else. When I said that will compromise the water proofing of the curb they said "well water will get in everywhere in the shower eventually" and also "we put silicone on the screw before we put it on so it won't leak" and if I replace the silicone every few years (the top part) it should be fine. So they are going to do that. I'm having them put in a frameless shower door and two stationary glass panels. There are not a lot of glass places to choose from where I live so I feel I'm stuck with them.

So here is my crazy 3AM idea. I'm thinking, to try and mitigate any potential damage..... what if I put a layer of Kerdi membrane under the area where the curb is going to be. Then wrap the wood that I put in the hollow area with Kerdi, then maybe even put a layer of Hydroban on it (the wood that I'm putting in the hollow) Do you think that is crazy or might that mitigate some possible damage. I guess the result might be water getting trapped in there, but heck maybe after 5 years I can take off an outside tile and shop vac any water out. I don't know. I've seen Isaac tear apart so many water logged curbs I'm leery of that happening to mine and I fear it might.

Ok, so is my 3AM idea totally cra cra? 😎