Why would you wait for a permission from the author? for the most part, if it's webtoon it's going to be TL into English anyway in the official site. There's almost no way that any author would agree with anyone uploading their works to different platforms, except if it's a twitter or pixiv manga, then maybe. This is almost the same case with mangakas, does every scanlation asked for their blessings when they translated their works, of course some did and succeeded, but that's a minority. And, still, if you're linking the raw webtoon link, then in the end ppl will read that one too.
Engga, ini esensinya sebenarnya bukan udah ijin apa belum, tapi sampe kapan bisa translate sebelum ada official English nya. Pengalaman, ga mau Author juga kalo di luar platform webtoon, mereka minta mending bantu buat webtoon fan translate. Nah masalahnya, ga semua series ada fan translate nya, dan emang susah buat orang bisa liat translasinya, ga kayak di MD. Jadi kalo tujuannya murni biar banyak yang baca ya.. gini, setidaknya sampai saat ini imo. Kalo udah ada ya di drop aja, ga susah men.