> Its a CMS, designed from scratch…

Maybe not scratch scratch: "And under the hood, EmDash is powered by Astro…"

> It's built on top of, and seems to perfer you use CF proprietary capabilities (D1 Databases, R2 for image/media storage, their workers for running things.

D1 is SQLite, R2 is S3, and there are other ways to securely run plugins. If it was designed to only be possible to deploy on Cloudflare, they didn't do a very good job.