I'm very surprised they are not running with the runtime. That seemed like Deno's secret sauce? The rest of it is very aligned with Cloudflare already, deploy, kv, workers, etc seems like the lower hanging fruit.

It's almost certainly not worth it. Having less software that you can keep more reliable is almost always worth it over having more software just because it's 10% faster or whatever. This isn't always true but it's mostly true.