I hate skirts, I find them to be a big waste of time, a small waste of filament with little or no value. The purge line in the preamble is plenty for my printer. I got tired of turning them off manually every time I used a built-in print setting. By editing this file you can change the built-ins although you have to do this again every time a new "settings update" is applied. In the future I might automate the process with a file watcher mechanism that will run every night or something. I also like to print with at least 3 parimeters and I slow down the first layer by 10% from the usual 20.
MacOS
/Users/<user>/Library/Application Support/PrusaSlicer/vendor/PrusaResearch.ini
/Users/<user>/Library/Application Support/PrusaSlicer-beta/vendor/PrusaResearch.ini
/Users/<user>/Library/Application Support/PrusaSlicer-alpha/vendor/PrusaResearch.ini
Windows
C:\Users\<user>\AppData\Roaming\PrusaSlicer\vendor\PrusaResearch.ini
C:\Users\<user>\AppData\Roaming\PrusaSlicer-beta\vendor\PrusaResearch.ini
C:\Users\<user>\AppData\Roaming\PrusaSlicer-alpha\vendor\PrusaResearch.ini
[print:*common*]
first_layer_speed = 18
skirts = 0
perimeters = 3
[print:*common*]
support_material_style = organic
top_fill_pattern = concentric
bottom_fill_pattern = concentric
# also trying these
#top_fill_pattern = octagramspiral
#bottom_fill_pattern = octagramspiral
# added
first_layer_speed = 18
perimeters = 3
support_material_style = organic
top_fill_pattern = concentric
bottom_fill_pattern = concentric