I never tried this as I always listen to stuff in WAV so never had it on as it obviously is intended for mp3 files, I thought or assumed it would not do anything with lossless as there is nothing missing for it to add to. If it still does take effect then I can only think it does overkill accentuate those frequencies (not in a good way!)
Might have a dabble later as I thought from memory trying DSEE years ago with WAV's I heard no difference




























