I would love to be able to mix a watercolor mode with the sketchy linework modes. It's very commone in architecture to add some quick washes to a pen sketch. Also, I have yet to see an engine include a watercolor filter/mode that actually has the emotion of watercolor. The current mode is too washed out and the colors are too pastel and crazy.
Look at traditional architectural watercolor sketches and try to capture that mood with the filter. The only digital filters I have found that come close are FotoSketcher and Waterlogue app by TinRocket. Reference these for ideas of what might be possible.
Hi, just wanted to check, have you tried adjusting the Saturation slider under the 'Image' tab in the Visual Settings? It might help if the current mode feels too washed out or the colors seem overly pastel.