I use that program/script by FLAK for all of my 2024 repaints. It may seem a bit complicated the very first time you're finding out how to install and use it, but you'll soon realize it is incredibly easy and saves a ton of time.
Once you have FLAK's files installed, there are folders included for the Albedo, Comp, Decal and Normals files. All you have to do is save all of your texture files as .PNG, place them in the correct folders for their type, and then run the script file. With the script file open, you just press 2 and enter, which will automatically generate all of the .XML files needed, and then you just press 4 and enter, and it will run the MSFS 2024 sim/SDK which will convert all of the .PNG files to the correct 2024 KT2X format, and will spit them out into a single Output folder, along with all of .JSON files.
I'm using Flak99's script as well, the only caveat is it converts png files to the new ktx2 files, so any 2020 textures that have been saved as dds files must be converted to png files first before using the script.