I think there’s a number of challenges with that approach, mainly getting a representative set of sample queries that will accurately optimize the reference VM. I wonder if harvesting the VM state at scale based on pages that are duplicates across machines might work of course then you have problems with ASLR and how to reconstruct a VM to actually use that data.
The more representative the warmup set the better the result but even a quite simplistic approach is helpful since much of what you want to optimise is not page dependent: the React rendering infrastructure, router, server, and in the case of Deno the runtime level code written in JS.
I suspect harvesting VM state from a production workload would be counterproductive to the goal of isolation.