It's an interesting idea Jim.

Not sure the current walls work for a cavern though - they're too regular. Might be better using Sue's cliffs for those too, though that might mean masking the top of the cliff symbols to make them look more like walls and less like cliffs.

Possibly a fractal polygon running out to the map's edges would be better to show it's a huge cave instead of using the cliff symbols though. If so, that would probably be better created using the Color Key Effect, drawing a suitable fractal poly for the cavern's interior, then covering the entire map with a "rock" bitmap fill texture rectangle on the same Sheet, and turning the interior fractal poly to a solid fill, colour 6 pink to create the cave. Oh, and moving the "cutout" fractal poly above the solid rectangle on that Sheet, of course! (Voice of experience...)

Does this mean the "dungeon" rooms and passages are then walls on the huge cave's floor, roofed over so from inside you can't tell you're in a gigantic cavern?

Indeed, much improved.

Maybe increase the glow on the numbers to make them more legible.

The Tower top looks very flat though. The outer walls need some sort of shadow to show the floor is below them. If it's the exterior top, that may complicate matters, as you'll need different length shadows for the higher and lower stretches of the wall tops.

Further on the latter point, and if they are, the crenellations need a little adjustment too, as there are what seem to be large open gaps at the northeast and southwest corners currently, which is not realistic.

Beyond the Keep Tower shadow issues, I'd suggest adding some shadow effects to all the wall towers, as they also look very flat right now.

Appreciating you may be tied to whatever the publisher wants, but you might want to add further smaller towers where the two walls join, or add crenelations along both sides of that main north wall after where the two link (on the "outer" side from the enclosed part). The crenellated wall ending at the thicker north wall just looks odd right now, because it leaves the south side of that main wall undefended.

If the brown roads/paths are just dirt, I'd suggest making all their junctions less precise (so not just where that "castle path" meets the main paved road), as unless something blocks them, folks will always cut the corner at such places, which will wear away the grass very quickly. Indeed, you might even want to consider redrawing the dirt paths as smooth polygons, rather than lines (or just add a few polygons to break up the precise edges of the lines in places; as long as they're all on the same Sheet, the Effects will blend the two into one). Unless there are obstacles, dirt paths end up getting broader and (loosely) straighter over time with use.

Shame there aren't any descriptions to go with these, though I appreciate that's not an essential requirement for the Atlas. Quite a lot don't seem to have any scale or north indicator though, of which the scale issue seems more of a problem, especially for anyone who'd only be using the image versions of the maps.

Yeah, I agree with Monsen regarding the text labels. There's also a problem that parts of the words on the paler text fade where they overlie the palest green on land.

I get the impression too that the roads are on a Sheet higher than everything else, so look to be overlying some of the text labels as well.

Might be worth tweaking some of the red dashed border line nodes to try to remove the odd long dashes in places, though this is a perennial difficulty and can't always be properly resolved, I know.

I'm finding the dashed roads a bit distracting. Partly, this seems to be because the roads cross over the settlement circled-dot symbols, so that could be simply part of the Sheets issue noted above. However, I think it's also partly because the roads often don't pass through the centre of the settlement symbols. While that can be a legitimate point on a map (i.e. the main road may not pass directly through a settlement), at this scale, I think it probably should be tidied-up.