I have an Orico enclosure case model 25pw1 and a Seagate ST500LM030 HDD, the case contains a sponge I think its material is EVA and the manual says to place this sponge in the lower part of the case but this sponge in direct contact with the lower part of the HDD and the exposed flat cable, will the pressure between the sponge and the HDD damage the HDD flat cable in the long term or is it safe?

There is no way this is a serious question, but on the 0.000001% chance it is:

Itr should be fine, the sponge thing is to stop the disk from floating around inside the case and keep it anchored properly. The case was probably made for a fatter disk, but they used this disk and needed something to anchor it down.