AzureWings' script doesn't use any particular precipitation profile, you can configure it to use the 6-step precipitation levels (or however many you want, for that matter). The quickest way is probably directly modifying the script using Notepad++ (comment out the "pColorTableDefault" and replace it with this one, if you're using the same RGB values as in my GIMP script):
The above should be fairly self-explanatory, it contains the RGB value of a given precipitation level, and the corresponding avg. precipitation in millimetres for that level (if you're using different RGB values, you may need to modify the values to match). I also posted some instructions about using the script that might be helpful.pColorTableDefault = {(210, 200, 250):300.0, (190, 170, 240):150.0, (150, 130, 220):75.0, (90, 80, 160):37.5, (240, 235, 160):17.5, (235, 0, 140):5.0}
The output from both my earlier GIMP script and AzureWings' script should be about the same, but the latter is preferable since it's more flexible in the sense that you can set up custom temperature and/or precipitation profiles easily, and it isn't tied to any particular program or a version (for example, I use GIMP 2.10 nowadays, so I can't use my prior script because that was made for 2.8 ).
EDIT:
There is always a lot of guesswork when creating a fictional world, though there are certainly more plausible and less plausible interpretations. Climates do have a fairly predictable overall pattern if you make the basic assumptions of a similar rotation rate and axial tilt (and therefore similar atmospheric circulation) to Earth. I might add that probably the majority of things in the Earth-based temp and precipitation maps that appear to contradict the rules of thumb given in the tutorial are only seemingly contradictory. If you have any particular examples of areas that feel off or appear contradictory that would be great, because that would help in identifying some areas or phenomena that might need extra instructions. Hey, who knows, maybe we'll eventually manage to come up with something a bit more thorough when it comes to instructions for the precipitation maps .
Oh, and any thoughts of "making a world whatever I want" are clearly heretical, my errand child. Listen to the great Azélor: science and formulae are the way. Trust in the method, my child, and pray for enlightenment. After all, you wouldn't want the climate inquisition to get you, now would you?