Doesn't MST merely chop up the bandwidth of the lanes you have? So why would you update different parts of a single display using MST (each stream only getting part of the bandwidth of the link), rather than using the whole link to update the display from top to bottom at the same pixel depth and clock?
From memory they use it on things like the Pro Display XDR (possibly some 5K’s too?) where the display supports DP1.2;
My understanding is, the spec doesn’t allow for 5K/6K at 60hz but does allow for MST to send two streams at up to 4K/60, so it’s a creative use of what the spec supports to allow a higher resolution than envisaged when the spec was published.
