Not yet in my speech, but you’re pointing out something interesting.
If you pronounce them as a single word, cuzall, cuzawesome, yeah, that’s a proclitic, and that’s grammaticalisation. I don’t.
I do pronounce ’cause as a single syllable often, many do. That’s a reduction, but I think it’s still independently stressed for me, and it’s certainly with a full vowel: coz /kɔz/ (Australian English), not cuz /kəz/. If you’re doing it as a schwa, that’s consistent with more extensive reduction of the word.
If you don’t mind: what’s your English dialect?