The latest beta release installers for MacOS, iOS, and Windows can be downloaded from the relevant github actions page. Look for the latest workflow run which has the “develop” label. Clicking on the title brings a page with the download artefacts at the bottom.
Building Csound from source or from the git develop branch is not very difficult on Linux, and can also be done on Mac and Windows. How-to descriptions can be found in the BUILD.md file included with the Csound sources, also available online here.