So this came out a little differently than I visualized, but it's still workable for me. The areas outlined in blue are where there would be inkable walls, providing near-direct access to the old spawns. The spaces outlined in yellow indicate where the grates would go; in my mind, these are there mostly for mobility reasons, allowing more room to move around. Those white arrows are supposed to show that the areas outlined in white are to be moved (I'd do it myself, but then the picture would look weird). It's kinda hard to notice, but the red outlines denote objects to be removed entirely. (Except for the one meant to be a yellow outline.) I did neglect to really move the spawns, but their locations should be obvious.
I'm thinking some of the boxes in the center are gonna have to go, and some barriers added in certain spots to prevent charger cheese/removed for redundancy. I'm not 100% certain of either yet, though.