I wondered about this for the Nintendo Switch Version, too!
While the PS Vita files are encrypted and I have no idea how to even start decrypting them, in your case it's a bit easier.
Your font files are basically nltx files with extra metadata. If you just open one in your hex editor, search for "NMPLTEX" and remove everything before that (so that the file begins with NMPLTEX), you can use nltx.bms I gave you in the other thread
to extract the texture. You can likely reimport it the same way you did with the nltx's, just don't forget to return the data that was before NMPLTEX.
Again, OneCombo, this doesn't apply to you, sorry