It's more than aesthetic, unfortunately. I believe the warping is actually getting worse over time. So like you I was thinking of drilling out the rivets so that I could work on the cage out in the open. Thanks for your suggestion!
I run a mini-ITX NAS inside a Lian Li PC-Q25. I love the case, but recently I noticed that its hard drive cage is....warped. See attached picture. Some of the disk guide rails won't actually fit in the grooves anymore. The fan mounting area is also affected. While I may be to blame for this...