Maplestory "High Five" Private Showcase

I think that explains why the update notes specifically referred to "drops from monsters in your level range" (event items are classified that way) and said their duration was increased to 30 seconds.

Yes, I think you're right, I've spent quite a bit on pets in KMS purely because it was so difficult to loot event boxes in time, playing from North America, I stopped to loot each time I killed something. I feel like it was already around 30 seconds, however, I never timed it and just went for getting a pet and not having to worry about it. So I guess, it looks like this change means nothing to us in GMS, unless they decide on a whim to switch to what KMS has somewhere down the line.

Oh, and I think it definitely explains why everything was set to disappear in 30 seconds in KMST, probably because they unintentionally changed everything to last 30 seconds.