White reflective coating over new capsheet=cool roof?

hi, i am a homeowner seeking some roofing advice.
currently have a low slope roof with capsheet that needs replacing in sunny (HOT!) los angeles. measures roughly 30x40 feet, 2 story- upstairs cooks in summer.

originally wanted an spf roof- mainly for it being insulated/cool/waterproof- but the prices $$$ and that i’d be “married” to it kept me from saying yes.

so i’m back to looking at good ole capsheet. plan to tear off existing and replace with new. and cover with a white reflective coating- primer + 2 layers.

there are alot of the white roof coatings online and they all say their product(s) is incredibly effective-cools/waterproofs, BUT i’d like to hear some opinions from real roofers- not ones rep’ing some product.

does a white reflective coating really work as claimed?- cools/waterproof? extend the life of the capsheet by protecting from uv ray damage?

i don’t expect it to be as effective in cooling as an spf roof but will a white coating over capsheet make the upstairs more tolerable in the summertime?

heres hoping the answer is yes,
thanks much, freckles.

You can get a white membrane-Tpo-Pvc-Epdm.Yes it will keep your house cooler and reduce your cooling costs.