An interesting comparison here maybe...
The Women's Elite TT featured a descent, U-Turn and climb back up as an extra to what the u23 rode. The checkpoints actually map out so that they rode the same checks as the u23 with just an extra section.
While Reusser obviously had a longer harder effort (she did the additional section in 11.32, which was fastest) Backstedt was faster in the first and second sections, and only dropped ten seconds in the split to the finish.
The sum of the u23 sections ridden by Reusser was 31.35, so Zoe's 30.56 was 39 seconds faster.
Zoe was faster over all sections than women elite silver medalist Anna van der Breggen and bronze medalist Demi Vollering.
With Vollering coming in 1.05 after Reusser I think there's a good chance Zoe could have got a medal yesterday