Question - local development vs Cloudflare

For local development, why does it run Nodejs and not miniflare?

I ask because I am trying to add sessions, and a database backend instead of IndexedDb (reasons), so this results in local code needing process.env access to env vars, but on Cloudflare there is no process.env, only context.env.

I thought that all remix-run projects should use miniflare for local dev?

For context, this thread talks about this problem.