I'm not installing it again, but I'm replying because someone else might find your answer helpful.
I used the desktop app. I was trying to make an animation of a photograph zooming out from a very close-up detail to a full frame image in a 15 second clip. The built-in pan and zoom filter only allows a small change in zoom. I tried finding a way to keyframe the positions to no avail. The thing about Rush in general is that UX feels backwards and unintuitive. For example, it took me a whole few minutes to figure out how to start the project because the blue button to move to the next step (the only step, so it's not like it's a click-through) is on the bottom right corner, away from the rest of anything actionable. Last time I tried using Rush was in 2020, no recollection on how to navigate this thing. On a 30" monitor it's just not in a place anyone (maybe just me) would look for it. I don't understand why I have to pick media before initiating a project either.
Insult to injury, when I treid uninstalling it, it wouldn't let me because they system claimed Rush was still running, even though I made sure it was closed. So there are tenticles that it seems to leave running even when you're done with it. Had to reboot to uninstall.