Cutting a ridgerest

I did that with a blue CCF foam pad and joined the pieces with duct tape n a way that facilitate folding. Here is a diagram showing the cross section:

Haven't used it since acquiring a neoair pad though:-)

The Z Lite works because each layer nests inside the next :

that does not work with the Ridgerest
A few years ago I made my version of a nesting mat using a blue mat and a Tyvek baking.
The idea was to use it with another mat, it would not work by itself.
It is around 1/4 of the size of a full size Z Lite when folded.

BTW, now that I see the full image of mine I remembered that I cut off those "straps" because they come undone or brake in use anyway.
I did use the combo (Neo Air and Crazy Mat) on snow a few times but prefer to just use an Exped DM 7 and take my chances with a flat.
(not that my example is what you were asking for but might give you some ideas)