Yep, there are a number of different symbols involved, which are all just different colours of the varicolor symbols. The symbols are simply added in an appropriate cluster, and stacked to look more or less like a castle.

Blast from the past there, Jim!

"Them!" (IMDb link) was one of the 1950s nuclear fear monster movies, and I think (as confirmed by Wikipedia - make of that what you will 😉), was the first to feature giant insects as the protagonists. And yes, giant ants can never escape from all of that for those in the movie-know!

Which brings us round to the final South Wing, presented as just a single Level. More or less, anyway, as there are a couple of places where the tunnels pass over and under one another, which again helps give a slightly variant appearance to this map. This time, the base layout came from the DF video that actually launched the very first Burrows pieces, as part of their "Dungeons of Doom" KickStarter campaign in June 2017, "Encounter 14: Khri Colony". The Khri are DF's giant insectoid monsters that make such burrows, incidentally. The final amended layout is thus:

A lower height range seemed suitable for the southern side of the Palace complex, given how the surface view sketch was drawn.

So that concludes the extra maps to go with Errynor Map 40, and by the time you read this, I expect I'll be off mapping some far-flung corner of the region or other. Or is it ALL just an illusion...

The East Wing runs to a mere two vertical Levels by contrast, based on images of a couple of layouts on the DF Discord, combined here with the usual additions and amendments, for all the final plans are much simpler than for either of the preceding pair of Wings, and clearly show their rectilinear original forms rather more. This was though quite deliberate, as part of the concept of the various Wings was to show differences between them, suggesting they could likely be put to different uses, and that this area was probably still largely under construction. Plus it wasn't only the layouts that had been getting figuratively tied in knots with some of the other maps!

Simplicity only counts for so much though, so the entryway from the Palace this time isn't on Level 1, but on the lower Level 2 (which is also a somewhat larger map than the others):

As mentioned, the four Palace Wings were based on a different option than the "Carapace" booklet's system, hence none of these maps have schematic drawings beside them. Each was instead based on images posted by various people on the Dwarven Forge Discord, and from layouts shown in several official company videos available on the Dwarven Forge YouTube and Twitch channels. All used items from the cast modular terrain "Burrows" pieces made by the same company.

The nature of such modular terrain items does make for more rectilinear layout patterns than those generated by "Carapace", although this would make it possible to set-up layouts on the tabletop, for those owning such Burrows pieces, that are similar to what appears in the Palace Wing layouts overall. However, alterations were made to the sizes, shapes and orientations of the tunnels and chambers at times as shown in the final maps here and in the following posts, so exact matches would not be possible.

Despite this change, the nature of each chamber in the Wings was again randomly decided using the Appendix 2 tables in "Carapace", with occasional amendments, since these offer the potential for a number of interesting variations and features.

The selected layouts were combined and chosen to loosely match the look of the outlying parts of the Palace on the Illusory Level 1 map, meaning the layouts delving deeper were placed in the western and northern Wings, representing the parts of the surface sketch where the taller buildings and towers were.

First then, the West Wing, comprising three main vertical levels:

All the Wings have just a single connection to the outside, in each case by a link back to either Level 2 or 3 of the main Palace. In this Wing, that's on Level 1 of this trio, where Tunnel W1.1 leads back down to Chamber 2.4 on the Palace's second Level. This layout was based on the extensive, multi-level "Demonic Depths" Build of the Month video from May 2020 by Dwarven Forge.

The idea is that the Wings are generally less-used than the main Palace, so few of the areas in them have suggested-use labels on the maps (albeit some additional comments are provided in the accompanying separate notes files).