backups would be either dnxhr 444 rgb, prores 444xq or cineform rgb 444 12 bit good enough for several generations. if you wanted pure lossless, like disney archive quality, you’d need exr half float 16 bit frame sequences using many terabytes of data.
and to be completely honest, you’d get much higher quality and smaller file sizes in mp4 h.264 in handbrake than adobe media encoder, but its entirely up to you. just use the masters you made in the first paragraph.