[jonas8732]

I have a 2.5" hard drive enclosure case and it contains an EVA sponge. As the material ages, does this sponge melt and stick to the HDD?

Does this sponge on the bottom of the case press and damage the HDD's flat cable?

[Borek]

Hard to tell. Judging from the composition it should be reasonably inert and not turn into a sticky goo, but it can depend on the exact composition. Many plastics contain additives which change properties of the original polymer/copolymer, so often there is no one universal answer that will cover every case.

It is definitely one of the things I would have no problems using in my computer. I used it in some cosplay costumes and RC models that I helped with, never had any problems. YMMV.