I'll mostly stay out of this discussion, but those wire shelves look hazardous to me UNLESS those gaps between the wires, & especially that edge gap, is completely enclosed, because snakes will naturally try to grab thru that & will eventually get stuck, even if it's just their heads.
***So I assume you know that, but just to be clear...for anyone else reading this too & looking to copy your idea- you don't want to install anything in enclosures that has gaps where a snake may get stuck- because even if they don't get stuck at first, their growth sorta sneaks up on us & then suddenly it's a hazard. And many things are very hard to cut thru to rescue a snake, & the process is especially dangerous for the snakes too.
Also, it really depends on what kind of snake you're keeping in this as to whether they'll be using a basking shelf or not, so again, you might want to clarify that since most members here may assume "BPs".
That's what I meant with the expanding foam, using it to fill in all the gaps so it's one solid piece. And this whole thing will be for my VBB, of which I've heard they like elevated platforms like this.