EF, we should club together with Shaun Gregory sometime and descend on an underpopulated Audax, giving it an average age in the 20s. That'll show'em
Won't work, just by coincidence an equal number of old gimmers will turn up, maintaining the balance.
Anyway, back to reflectives...
Based on my memory of the description I saw of the various standards I'd say "no" given that the standards say that the retro-reflective bands have to continue around the whole body, so a vest like that probably won't do.
(That rema link below says "bands encircling the torso".)
Obviously there's compliance with the standards and compliance with the PBP officials. They may look at that and wave you through, then at one control in the dead of the night one of the officials may give you a time penalty because it doesn't meet the full standard.
C'est la vie.