No research on most plant extracts, shea has a very low SPF of about 2. IIRC the cinnamates are chemical screens and only block UVB not UVA but both damage the hair, most chemical agents are unstable and break down in UK light.
UV damage of the hair. [Coll Antropol. 2008] - PubMed - NCBI (link below will download the full text of this review),d.d2k
Photoaggravation of Hair Aging
[Effects of sunscreening agents and r... [Tidsskr Nor Laegeforen. 1998] - PubMed - NCBI

My other concern with most sunscreens products is using enough to get a decent level of protection, think what a thick layer you are recommended to apply to your face and body, it's not a thin moisturising/ make up/ conditioner spray layer. There are many reasons you never see an SPF on a hair protection product, just very vague hints of what they might do.

Coconut oil as a deep treatment will help reduce protein loss from UV damage because of the affinity for structural proteins, but it's not providing UV protection. For example it likely won't prevent the protective cell membrane complex being destroyed, cuticle damage nor the melanin pigment being broken down which increases porosity. Some antioxidants (is that what you mean by blueberry and coffee extracts?) will protect from free radical damage but not against the other forms of UV damage, like chemical agents they get 'used up' or broken down quickly.
Originally Posted by Firefox7275
Goes to show the knowledge varies on plant SPFs; the last commenter here claims that shea butter has SPF 15. (Then again, the red flags start to come up when the poster mentions water for sun protection. whaaaa?)

Meanwhile, I am pretty much parroting the blurbs on the backs of the blueberry- and coffee-extract bottles. Not a word about the what-how-why of these protective properties, just touting that the extracts (all of which do happen to contain antioxidants) provide sun protection.

NC's list of ingredients gives a few UVA absorbers, of which dibenzoyl methane appears in this spray, which I CAN GET here in Berlin! (couldn't find many/any with PQ-59.) I'll get that and a Buff or two Any advice on how not to squish curls while rocking the Buff?
2c, med-coarse, dense, high-med elasticity and still working out my porosity. Living in hard-water Germany.

Still learning the HGs. Latest faves:
Washing with KC Come Clean or CJ Daily Fix
Conditioner Deva OneC, Darcy's Pumpkin Seed
Goin' Deep: CJ Curl Rehab
Loving a good prepoo with coconut oil
Styling with CJ CCCC Lite, KCCC, BRHG, and a spray gel (Fructis, JC Gelebration)

Second-third-day savers: Curl Fuel overnight and KCSS in the morning!