So time attack is "just" trying to set a PB on that particular climb? Sounds like a fun way to train, and should teach a lot, e. g. when to add power to keep momentum and when to use a feature to rest a little.
Judging from the picture in the Strava activity you posted here, his W/kg must be through the roof …
Yes, just learning how to climb quickly. How deep you can go, if and where you can recover.
I want him to understand his heart rate more as this is the best way, assuming your fresh, to pace a technical climb like this.
But today was just about following the wheel, the lines etc.
I've been telling him to sit on mine and Yamada's wheel on climbs and just look at the cassette.
Mimic every shift. That's a really good way to learn how to climb efficiently and effectively.
And of course, there is the big motivator of beating your own time. And then understanding how you did it. It's too early for recent training to take effect. Today it was due to proper rest and good pacing.
The fact that he is motivating me to train hard is just a bonus!
Andy