Extrapolating from Gee's strava and the point they turn on to gravel, which Gee did 53 seconds later - and assuming they started at around the same time - I get a time of 31'54 for Yates on the tarmac section for a VAM of 1833 on the asphalted section - which is a higher VAM than his Alpe di Mera record from 2021 which was 28 minutes at 1820 for a W/kg of 6.5 estimated, but it must be said this was at 9.05 rather than 9.9. Gravel section would then be a 1620 VAM, which is a lot lower but it's also less steep on average.
The strava sections don't quite add up though, and we always gotta take them with a pinch of salt though.
Also interesting, Gee was slower on the gravel than the 2015 GC group minus Contador.