Hmm… on my work iphone (iOS 18.3) I don’t see an option to change photos taken to JPEG XL. Only options are:
“High efficiency” = HEIF/HEVC
or
“Most compatible” = JPEG.
I do wish the “High efficiency” option would be JPEG XL instead.
HEIF is garbage. It has royalties and it’s inferior to JPEG XL.