VNAV PTH descent:Probably "cut and pasted" from 777 FMC software algorisms, so that explains the lack of understanding (software program) of the "wing design" on the 787 and the differences VNAV has on wing efficiency, betwixt 777 and 787 (both wing designs are super brilliant).The same applies to the 747-8 (over speeds on VNAV PTH descent) leading to VNAV SPD and the impending VMO/MMO!