This is not a wrong idea but would make the "All-Stars" idea even more vague. I would support Lifetime to make the Fanvote Redemption used for the early eliminated contestants so that their second chance in the original series make more sense. I don't think either Amanda or Kate should had returned, honestly, not cuase they're bad designers, but the original show is more about new entries.
Personally I would really love to see international contestants like Chấn Hưng or Elena Pignata, but we know very few reality shows would like to pay for airline fees.