0.15mm nozzle slic3r PE settings??

I tried to look for settings here: https://github.com/prusa3d/Slic3r-settings/tree/master/Slic3r settings MK2S MK2MM and MK3/printer

Sadly the lowest is 0.25mm nozzle, are there any guide line how to take the settings for a 0.25mm nozzle and change them to work on a 0.15mm nozzle?

for the giggles here are my current 0.25mm settings, first pic is the printer settings and as you see they are for 0.15mm nozzle... they are the easy ones as it just the nozzle size and some extruder settings https://imgur. com /a/GiBfr

remove the space before and after com

 

after printing 4 marvins i found out that the 0.25mm nozzle settings also apply for 0.15mm except for extrusion width

for extrusion width i calculated the % difference from nozzle size on 0.25 and applied the same % difference to 0.15mm


a marvin takes 5½ hours, and the only defect i see is the lower side of the ear's. i guess this is due to not enough cooling. so either i have a weak fan or its not directing the air at the part even thou it feels like it