Hello,
I’m using an Arduino uno as well. Mine doesn’t sit flat either, but it works beautifully. Just be careful when you pull it off or else you might bend some of the pins (pull it straight out so you don’t bend anything).
So to answer your question, the MOVI Shield will work fine, and you won’t ruin it. Just make sure to push it in and pull it out straightly so you don’t bend anything.