I think it would be worthwile to lower speed on overhangs and add more cooling on overhangs. That should clear up those patterns.

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You could use gyroid infill. It is more tolerant to flow as there are no crossings.

If it’s in corners only tune Pressure Advance, but as this is on the first layer it’s probably only the first layer, which is generally different from subsequent layers. Check the same thing on a higher layer to make sure that there really is a problem.

You can set the minimum extrusion width to a small value (20-25%) for better fill. You could also use classic mode with gap fill. You can use ironing for both to improve the results.

Does your slicer have Arachne slicing mode? It will use variable extrusion width which will help to prevent most of those gaps.

Room-scale DnD dungeons anyone?