The way I read that is if you expect tripping then minimise it. Under a normal situation in a domestic setting you don't expect any RCD to trip whether its an RCBO or dual RCD board. However if you have a bank of computers that have a bit of earth leakeage then you might get unwanted tripping so use RCBO's instead.See Reg 531.3.2 unwanted tripping (ii) rcbos should be considered. Also see section 314