Thanks for the advice. I actually ended up removing the spacer, biting off the ends of the screws, and closing it back up. Took the risk since the alternative (paying to send the thing back, buying a new one for more, then waiting for it to arrive) was just unappealing.
I did read that a lot of people do this mod, and the 9.5mm version is essentially the 7mm with the spacer installed. So I ignored Crucial staff who told me to get a new drive
and modded it anyway.