Chunky printing in perimeters and infill

I’m starting to see some issues with a few prints. Specifically when I slow down the print or print small features. The perimeters and infill get a little chunky. I’ve attached a photo to illustrate what I’m seeing (posting more tomorrow when I can). I have a hunch it has to do with heat creep. I stumbled upon the post with a fan shroud that blows air on the Budaschnozzle. Can anyone confirm that this is the issue and the improved fan shroud design will help?

Thank you!

What are the settings in slic3r?

Slicer settings:
Layer height: 0.1mm
Infill: 70% (normally don’t go this high)
Infill Threshold: 120 (This one I usually don’t adjust. I was experimenting because there were small features in the part)
Speeds: all 30 or less
Default extrusion width: 0.125 mm
Fan speeds: Min 0, Max 65

Attached is another example of what I’m seeing, but the settings are different.

Default extrusion width: 0.125 mm

That is awfully small. What size nozzle (as default the extrusion width should be the size of the nozzle like .35mm