Don't overthink this. I have most of my CD's copied into iTunes. They are there either as mp3's or as aac's, it doesn't matter.
Don't use iTunes to copy them to the SD. Go into your Windows directory, find the music files. In my case there's a folder for each performer. Click on that and you'll see a subfolder for each album.
Copy/Paste or drag the album to the SD card.
I plug that into the RV's radio, switch to "auxiliary input" and everything is there to scan through including all the data for the track.
