As far as I know, you can't auto-follow their follows, but you can auto-follow their other lists, by pressing "Duplicate" on Listr, like for this list
Discussion
auto follow is dangerous - there can be rouge npubs n u follow fake n add them to own profile
always each npub with scrutiny - having pseudo name handle is ok but imitate another already famous is bad
follow eeach npub in list one by one ok or just read content n notes of list of npubs or bookmarks segregated from line