That would be the end goal - but since all users get cookies there's not obvious "I'm anonymous" vs "I'm a signed-in-user" differentiator I can use to control whether to cache or serve live.
It'll happen, shortly, but the fastest solution was to re-deploy on a scaling platform.
It's now setting with 4Gb of RAM, and a load of ~40.
The single biggest issue is that the front-page either shows "marketing" or "your details", so it is dynamic and being generated on-demand.
I'll update to cache.