I use a free software called Bulk Rename Utility, it's got a nice interface with plenty of options for how you might want to rename files!

Make sure to use BRSO Articulate if you aren't already! 💜 It's super helpful because you can assign keyswitches to the note colors in the piano roll so you don't have to remember where the actual keyswitches are. Takes some work to set up initially, but then it's set forever!

Now those are my kind of flags! ✨