I did have a battle with layer 3, but completed ripped both layer 2 and layer 3 of Level 5, which is a laboratory.
-you can view the sample level to see how both the BG and layer 3 are set up.
-the palette for layer 2 is organized. While is uses palette 3 and half of palette 4, it should be easy to edit once you get the hang of it.
-while layer 3 does have a lot of detail, the caveat is that it uses all layer 3 palettes. That means the DKCR Sprite Status Bar, Minimalist Status Bar and the newly Remove Status Bar can be used.
-layer 2 can be used in full 512x512 detail.
-layer 2 uses 384 8x8 tiles, meaning it occupies BG1, BG2 and BG3. FG1, FG2 and FG3 can be spared.
-layer 3 uses 264 8x8 tiles. It uses 3 ExGFX files.
-BG does use 282 Map16 tiles, or a little over a Map16 page.
-Both layer 2 and layer 3 have their own files required to insert.
Attention, users. It uses the entire palette 0 and 1 and the layer 3 gets cutoff, so it's essential to use a custom status bar like Minimalist or DKCR status bar to use these graphics. Great rip, though.