If you're finding the mapping a drag, and not really enjoying it, it may be worth considering a broader-brush approach to the city overall - such as the Watabou style, that shows general areas only, with just a few important places highlighted, roads and general layout. Then if you feel so inclined, you could add detailed areas for selected spots as separate maps - that way, you don't need to worry about how the map looks zoomed out, and can pick area sizes to better suit the time and energy you have available for detailed mapping.

As Sue said, what you've shown here looks good in detail, but if it's not inspiring you, it may be worth a rethink, if only for next time.

I like the idea of the individual structures. There are times when it would be nice to have that option with some of the overland styles, so you could have smaller settlements - and indeed even larger ones - with more individual character, especially for smaller area maps (which, to be fair, isn't really what most overland styles are geared for). Other styles work well with just a single set of settlement symbols, however (makes recognising the different types much easier!).

An all-map greyscale RGB Matrix effect usually works fine to convert colour to black and white - that's what I did here with some hex maps, rather longer ago than I'd thought!

The creator of the HighSpace style, Joe Sweeney, did a series of tutorial videos when this was released (so for CC3, not CC3+), which are still available on YouTube. There is a link in the CA70 HighSpace 2 PDF Mapping Guide (there isn't a Guide for Part 1), but it goes to the wrong place. This link though takes you to the right place on the ProFantasy site, where you can download the videos. If you'd prefer to watch them online, they're here instead on YouTube.

Just wondering if the rivers, lakes, sea and roads might not look better in this style with a darker outlining glow effect, closer to the lines used for the buildings and mountains. That might then need thicker lines adding to the trees too though. Might make the whole too cartoony though. Never easy... 😏

There are already hand-drawn options for dungeons, including the Handdrawn symbols from SS2, for example, albeit not in an identical handdrawn style to Ralf's overland style.

For the kind of basic layout you drew, there's also the Create Your Own Style pack from the first Annual, which comes with the basic OSR-style "blue" dungeon style, which is very straightforward to use, and very forgiving. You can maybe get a better idea of what's possible with it from this Atlas map I drew in this style back in 2023. That's extremely easy to recolour to not be blue, if you prefer!