Redownloading Apps In App Store

Hey peeps,

I have a query.

If, in the App Store, I needed to redownload an app that I have purchased, and the latest version of that app was not compatible with my macOS version because it's not the latest macOS version, then which version of the app would download? The latest version? That would be horrendous. Hopefully it would download the latest version that is still compatible with my macOS.

This is an issue that I'm thinking about as I'm choosing to stay on El Capitan so that I can maintain compatibility with Logic Pro 9, as I still have Logic Pro 9 projects that I'm working on. But the latest version of Logic Pro X (10.3.2), which I also use, is only compatible as far back as El Capitan. Now that Apple have just released a new macOS (High Sierra), they may also soon release a new version of Logic Pro X that is only compatible as far back as Sierra. If they did, that would mean that there would be problems if something bad happened to the Logic Pro X file on my Mac and I needed to redownload the app, but the App Store would only let me try and download the latest version of the app, and that version was not compatible with my macOS version. I'm wondering if it would be a good idea to backup my Logic Pro X file.

Cheers,

MM