[RogerButton33]

Perennialism is outright Kufar and anyone who knowingly agrees with the Kufar , endorses it or does not call it Kufar is outside the fold of Islam. I remember Imam Anwar Shah Kashmiri ra has a Fatwa on it which was earlier shared by a brother in a thread concerning Perennialism.

I would be more worried about the state of your imaan then anyone elses brother. Do not use the kafir word lightly.