helm-find-files seems to always display an absolute path such as "/home/joebob/foo" instead of "~/foo". After many many years of seeing relative paths when finding files in emacs I find it oddly disturbing to be confronted with the absolute path.
A quick test using ivy and ido demonstrated they prompt with the relative (eg: "~/") path out of the box, just like the builtin default find-file.
I could not find anything in helm's customize set that seemed relevant.
Also I tried adding (abbreviate-file-name...) in the upper layer of the helm-find-files code but once it dove into the helm core the path was "normalized" back into an absolute form and I've been unable to figure out why, or even where.