Have you seen any actual weights for that frame versus P5D? I see that P3X is something like 16% lighter than the P5X, and the bars are ~13% lighter, but I don’t know what that equates to in real terms as I have only seen complete build weights, so I am not sure what the frame is contributing to the overall.
If the weight of the frame is 1-2lbs different, that can easily be made up for with potential drag savings (depending on which is actually faster per my earlier comment). Using BBS, and looking at the LP 70.3 course from this year as an example, 2lbs lighter gets 20s savings (@ 229W), but .002 CdA (~20g I believe) gets 23s. That course has 4000’ of climbing and weight is still pretty negligible compared to other factors.