You'd be hard pressed to beat Purley for the number of daily attachments/detachments.
4 to 5 attachments and the same number of detachments in the peaks, 2 attachments and detachments per hour off peak.
Some days it goes smoothly, others it's a total mess.
It only needs one portion to be late or for a driver to be displaced for the whole stack of cards to collapse.
I see the benefit it brings of reducing the overall number of trains through busy junctions, but simultaneously it introduces a major potential failure point into a trains journey which has a disproportionate impact when things aren't running smoothly. For that reason I'm not much of a fan of the practice with trains in service.