I highly doubt the protein is giving you frizz. The only thing is I'd add enough moisture to take the "crispness" out of your hair, sounds like you've already been doing that. Your hair can get a little more frizzy if it's also crispy, but if it's not crispy it's not the protein that's giving you frizz. Be careful in how much moisture you add back though. Fine hair can get very easily over-condition, so you'll want to add moisture back after a PT but not so much that it undoes what the PT did in terms of protein-moisture balance. I have this issue frequently. My hair is never dry nor crispy, and all my products have protein (plus I add CNPF to my protein ROs) and I do PTs weekly! I just use non-stripping low-poos and good leave-in conditioners. I haven't DTed in months and I haven't needed it.
Honestly it sounds like a buildup issue to me. Is Joico KPak the only PT you've been doing? I'd recommend not doing this one, and doing a "cleaner" PT like the gelatin PT. KPak has mineral oil which could be building up. If you want purchasable PTs I'd recommend the Spiral Solutions one.
Check the Pantene product and any other product for polyquats. Many curlies have severe buildup issues with these and need sulfates to remove them (with 4, 7 and 10 being the biggest offenders).
fine - low porosity - medium density - normal elasticity
Tropical climate: rain, rain, hot and humid, very high dews
Low-poo: CJ Gentle Cleansing Shampoo, Giovanni 2chic BK&AO
RO: JMO Bare detangler, Giovanni SaS, SheScentit Okra
Styler: FSG with CNPF, CJ Pattern Pusha, Volumax Mega, Ouidad Climate Control
PT: IAgirl's gelatine, CJ Repair Me
Experimenting with: CJ haul!
iherb discount code: CFN646