If you want to keep the temporary files (the tiles) when using the large exports annual scripts, you can just comment out the line that deletes them from the @Annual\Issue 129 - Large Exports\tile.cmd script:

DEL /q tile*.png

(This line appears two places in the script due to branching paths)

Do remember that this also means you need to manually clean them out before doing the next export however, or the stitching process will get confused.

And if you just want the tiles generated, and not stitch them together at all, you can comment out the two lines in the script starting with magick mogrify and magick montage.

And yea, you do absolutely need to use png when working with large images, as stated above, jpg cannot do these image sizes. But if you just export things as tiles from CC3+, you could switch that export to jpg to get jpg files instead of png tiles, since each tile is small enough, it's only when stitched together it becomes too large.

In the final deep zoom images I have made for the atlas (like Sanctuary) I exported as png from CC3+, but the final tiles used by the deep zoom script itself are jpg images as this gives much better performance due to smaller file sizes.

They way I am envisioning a huge ship like this isn't huge individual areas dedicated to one thing, but more like divided up into "residential zone A", "residential zone B" and so on, where each individual zone have all the services needed for that zone, such as kitchens, storage, living quarters, recreation, security and more. Each zone being more or less self-contained (maybe even designed to be able to be isolated in the case of an emergency.

Actually similar to how a city today works. You don't find all the kitchens of the city in one corner, they are distributed out so people have access to a local restaurant without crossing the entire city.

Outside the residential zones which contains everything needed for the citicens, you may have some large engineering sections (but even a lot of that would probably be part of a residential zone, you can't risk having all the oxygen production in one part of the ship), maybe a huge hangar deck for the main transport ships bringing supplies and people on board. Maybe a command section, but that again probably would just be a tiny spec at this scale.

Yes. If it is already a symbol in the drawing, go to Symbols -> Symbol Manager, select the symbols from the list, and use the save as catalog to create a new catalog with the symbols.

If it isn't already a symbol, but just loose entities, you can define them as a symbol first using Symbols -> Define Symbol, and then you can export it to a symbol catalog file as described above.

To add it to an existing catalog, do as above, then open up the existing catalog for editing by opening it up using file -> open as opposed to just open it in the symbol catalog window, then go to Symbols -> Symbol Manager, hit Import, and pick the catalog file you created above.

Did you try inserting into a new map in a completely different style? Still trying to figure out if this is something spesific to that Cosmographer template, or if it a general problem for you.

Oh, and since nobody remembered to ask this yet as far as I can see, you have installed the latest CC3+ update, right (3.98)?

Are you putting the image on it's own sheet? Not that this is required, but it makes it easier to handle to avoid for example the image ending up behind the background or similar.

When you insert the image, do you properly give it two corners as the command line asks for. The two points you provide as corners determines the size of the inserted images, so if you click two points really close to each other when inserting, it will be tiny.

Also make sure the image is actually a png image. Try to open it in a local image editor or something. Lots of websites does weird things, so you may have accidentally ended up with the html code for the page saved with a .png extension instead of an image.