Insert baths with no integral upstand need the walls around them fully waterproofed up to 150 mm over any rose connection. A wall-recessed bath without a shower above needs an integral upstand lip along the wall sides, full waterproofing of the bath to wall junctions, and water-resistant walls around it up to 150 mm over its rim.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.