Slab Storage - Intercept Shield Boxes?

I just started collecting PCGS slabbed coins for a registry set, and I'm going to be putting them in a safety deposit box. Right now they are in a PCGS blue plastic slab box.

I read about the Intercept Shield boxes, but their track box which fits the slabs seems to be sold out everywhere for over a year, and all they have is the red box which is much larger than I need and lacks the tracks to fit the slabs.

So I was thinking of perhaps making my own track box by buying a few of the Intercept Shield 2x2 holders, removing the intercept part and putting it inside the PCGS slab box. I figure it will still have the same effect. I have a couple of questions:

1) I've never handled an Intercept Shield 2x2 before. Can the intercept part be removed from the clear plastic part, or are they attached together?

2) If they are attached together, I assume it is attached to only one side of the clear plastic slab, so that I can still leave it exposed?

3) Does anyone think this is a bad idea?

4) Do I also need to put some kind of silica gel insert inside the box as well to protect against humidity or does the intercept shield already do that? And if so, will there be some kind of unwanted reaction between the intercept shield and the silica gel or do they "play" well together?

Sorry to ask so many questions, but I'm new to this and want to keep my coins well preserved. Thanks!