Chevra, nobody is perfect. Rav Shlomo did his best, and I know many, many people who he sent to the best yeshivish. He changed a generation. He was accepted by major admorim.
Please remember that you don’t know where if your niggunim come from. There is a popular niggun used for havdala that is from the conservative movement. But it’s used.
If you don’t want to use a niggun, don’t. If someone finds beauty in his music, then use it to connect to Hashem.
The last thing HKBH, or Rav Shlomo would have wanted is a machlokes.