No Bounce Recording on the BR-800?

There is no explicit Bounce record function on the BR-800. Why not? Do you need it?
Bounce recording is where two or more tracks are merged onto another track. Very useful on my Micro BR which only has four tracks, but I never really need it on the BR-800. Six tracks (four mono, two stereo) is plenty for everything I ever do. However, in this video I try bounce recording, using Mastering.