You should think about uploading a higher-res version of this to your Forum Gallery (maximum size there is 8 MB).

Like many things in CC3+, Layers can be powerful friends once you understand what they can do for you. Aside from the unique feature of being able to freeze and unfreeze things on a layer (something you can't do on sheets) - very helpful when trying to select something as long as it's on a different layer, for instance - as Don mentioned, you can easily hide or show entire fresh versions of your map using only layers. You can even toggle them by writing a little macro command, so as to do that with one click! Plus you can hide or show entire rafts of terrain or symbols, so long as you make sure they're on the correct layer. Like the GAME MASTER ONLY layer for hiding all kinds secrets the players shouldn't see (yet)!

Must admit, I've sometimes wished there was a way to group layers together, just as you can group sheets onto layers, so you could turn off or on an entire set of different layers at once. That's probably just me though 😁!

Note though that the edit function doesn't work on smooth entities, only straight or fractal ones, and you must have used a drawing tool to create the original entity as well, as far as I'm aware.

Hydrothermal and other undersea vents come in all shapes and sizes, much as they do on land. As I was working with the deep ocean floor, I wanted something like those relatively recently discovered with entire ecosystems, all with no reliance on sunlight. No plants, naturally, but a fascinating variety of creatures that congregate there. No reason you can't have them just as you've illustrated here, certainly!

It looks to me as if two of the Throne images have been omitted from the set with Temple of Bones Annual, simply judging from their name-labels and the fact the Chair symbol has all four options correctly.

If that can't be resolved, I found some ornate chairs under the Perspectives 3 Bitmap B options that might work (one is varicolor):