Heresy against Catholicism means little to people outside of it.
If someone isn’t convinced that the Catholic church is what it claims to be, then the charge is meaningless.
What’s important to Christians is whether the charge can be made of being against the teaching of Scripture, not the teaching of some denomination.
Make sure you tell God that if you meet Him.
It does mean something to former Catholics.
With Catholics the "church" supersedes scripture.