I don’t mean to add to the fire, but for those requesting Catalina support, please note that this is an alpha version of the software. This isn’t meant to be the final version. Keep in mind that when the final version is out next year, hopefully a lot more institutions will have updated to Big Sur so that the community can use Infuse.
On a more technical level, I can’t speak for the codebase of Infuse itself, but I develop for iOS and macOS platforms. Big Sur does introduce a lot of features that allow minimal work to be done to port software from iOS/tvOS to macOS. That being said, this is no easy feat and you can imagine that a development team would want to focus their efforts on supporting the latest version of an OS for the first release of software on that OS.
Awesome job to the dev team on this and I’m excited to keep testing the alpha for weeks to come