I get foil highlights every six weeks (when I get my haircut.) Don't feel that it affects my curls at all. It's only about 5% of the hair that's actually involved in the process.
3a (Corkicelli), highlighted, fine, low porosity

HGs: Anything Sevi; Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; UFD Curly Magic; Botanical Spirits Jellies, CJ Repair Me, Aloe Fix