[vladimir998]

“No hard feelings, brother. :)”

None at all. If you’re baptized, we have the same Father whom we can call on as Abba!

[CatherineofAragon]

"None at all. If you’re baptized, we have the same Father whom we can call on as Abba!"

I am baptized, yes. And you're right. What a blessed reason to rejoice.

[piusv]

They are still separated brethren and technically heretics (if not formally, materially).

Heresy is the obstinate post-baptismal denial of some truth which must be believed with divine and catholic faith, or it is likewise an obstinate doubt concerning the same;

Objectively they are heretics. Therefore, using the word is certainly valid and in no need for correction.