Hi, You can completely change the icon, yes you need the rcedit for sure, then you need to set the project settings and export settings to use your final .ico file, but how you can make a standard icon file? answer is using my script for windows ;) :
@echo off
setlocal enableDelayedExpansion
set sizes[5]=16x16
set sizes[4]=32x32
set sizes[3]=48x48
set sizes[2]=64x64
set sizes[1]=128x128
set sizes[0]=256x256
set newnames[0]="zero"
(for /L %%i in (0,1,5) do (
set newnames[%%i]="%1_!sizes[%%i]!.png"
magick convert "%1" -resize !sizes[%%i]! PNG24:!newnames[%%i]!
))
magick convert !newnames[0]! !newnames[1]! !newnames[2]! !newnames[3]! !newnames[4]! !newnames[5]! icon.ico
del !newnames[0]! !newnames[1]! !newnames[2]! !newnames[3]! !newnames[4]! !newnames[5]!
save this script as img2icon.bat and then download this ImageMagick and put its path to environment path variable, (also it's better to save your script inside imagemagick folder).
that's it :)
Usage:
img2icon YOUR_IMAGE_FILE.png
now this icon is completely standard and has the all sizes inside itself. I tested it.