I am on Fedora Secureblue where KDE Connect is removed as it cannot be easily disabled yet. To reduce attack surface in local networks, it is removed. (Is that correct with all ports closed in the Fedora Firewalld?)
Note: if there is a reliable way of deactivating it fully, it could be added back again.
An idea would be a rootful podman container, using Distrobox. But I am not sure if this is possible, if it could interact with the system etc.
A Flatpak would also be stunning, but as KDE Connect interacts with so many parts I suppose there would be missing features?