The biggest hurdle to supporting additional distributions is time - LibreTime requires a host of system packages and some of those dependencies are very version specific (for example the major version of Liquidsoap). For every release, each supported distro needs testing. There are 2 people working on LibreTime at the moment. We welcome additional developers and if you wish to contribute, you are welcome. However, posting full, modified install scripts to your website is not a useful contribution to the development process. I’m sure it is helpful for other people trying to install LibreTime on Fedora 34, but it doesn’t work as a patch (See 2.4.8 of the C4). A pull request is a much better form of modification that we can work with.
Fixing distro-specific issues also requires knowledge and experience with that particular distro. A bug on Fedora is not necessarily the same as a bug on Ubuntu. @joola and myself understand and are experienced with Debian and Ubuntu-based systems, so we are comfortable maintaining support for those platforms. Additional platforms (e.g. Fedora) are welcome, but they need to be backed by someone who is willing to put in the work to help maintain them long-term. A drive-by contribution of a distribution is not going to work because we lack the workforce or experience to maintain other distros.
The current way distros are supported is deliberately built so that it can be extended - adding an additional distro requires some updates to the install script and the mapping of package name to distro release for each component of the LibreTime system.
If you would like to see Fedora 34 support, that is great! I look forward to engaging with a pull request. I am also happy to help chime in on any guidance you may need in Expanding LibreTime: Need help with packages.py - #3 by rtroy