Good list of proteins:

Some other ingredients behave like proteins or react with the protein in our hair so some watch for them, too: AVG and coconut, for example.

I just double checked: CG book states to avoid parabens in gels but doesn't mention them as far as conditioner, aside from saying they are a preservative and controversial as some deem them as unsafe. So, I guess it depends on the product it's in as far as 'official' CG. My apologies for that questionable information - I should have looked first.
remember, with all advice or suggestions for your hair, YMMV!!
My hair:
2b wavy, medium texture, low porosity, med-high density. Protein finicky.
My routine:
Cleansing: DCNP, every 4-5 days (occasionally use CJ cleansers).
RO: CJSC, occasionally use JCDC
Gel: KCCC, CJCIAB for 2nd day hair (sometimes third)

Heat is my friend: warm water rinses, steam caps, and diffuse dry. I love CLU cloths and my Denman.