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
https://listr.lol/npub1te0uzs6vj29umjaxlqqct82j8q6ppyefrxq06dhr8d6pvwfatgkqjmjgwp/30000/naddr1qqgyummnw3e9getrdpxkzu3jxqergqgkwaehxw309aex2mrp0yhxummnw3ezucnpdejqygz7tlq5xnyj30xuhfhcqxze653cxsgfx2gesr7ndcemwstrj0269spsgqqqw5cq966494