Is that an issue with the format or the currently available tools though?

Fdroid is a secure repositorie and the applications are reviewed before being made available for end users.

Reviewed by who though? Malicious apps even get through apple and Google’s screening. I can’t see how fdroid can match the capabilities of those guys.

Any brands you would recommend?

I’m curious which part you think is overkill and how you would redo this? I have a proxmox cluster and run docker amongst other things, but haven’t set up any sort of high availability.

I don’t need live migrations, but something that could help with load balancing and reducing any potential downtime if a host fails would be great.