I commented somewhere else already, but you can search directly from qBittorrent. Search by title, then filter by "Remux" or sort by size. Keep in mind tho that

I commented somewhere else already, but you can search directly from qBittorrent. Search by title, then filter by "Remux" or sort by size. Keep in mind tho that a blu-ray release must exist in the first place, and that some 4k blu-rays are just not very good to begin with (upscaling and what not).