Any chance for Mojave support? It currently requires Big Sur. Looks good on screenshots tho.
They don't even make it particularly easy to script an installation of an older version in a VM. There are 3rd-party tools but they're usually just as complete & compatible as whoever wrote them needed them to be, and/or they're abandoned.
[EDIT] like the VM images Microsoft provides. Those are wonderful.
Regarding Mojave... Yeah I still use that daily. Catalina is a mess, and Big Sur can't be (officially) installed on my mac. I could've tried to have a go at backporting the OP app, but Swift is too annoying of a language and I don't know much of it.