For now, huge asset pack are uploading in .zip, i think it can be better to be in .pak file instead because this will allow to support extra features such as :

A way to use encryption:

When the user upload a assetpack that wants to be encrypted, on the nanos assets website, there is the encryption key that the user can put into his server. It will function like a vault api key, and the user when updating his asset pack, can choose to regenerate randomly a new key. This key will be used to decrypt the asset pack so only his server can use this asset pack.

The rest of my idea is based on my other idea here : https://feedback.nanos.world/ideas/p/vault-assets-pack-as-collection-of-assets

For the compression, the .pak file could be used to store all the references of a asset (So a static mesh name pak file will also include the materials, textures, ...)

For the encyrption, there will be no need to seperate each assets in the pack individually since theses assets will not be used in any other asset collections since it is encrypted.

Here is some ressources i found online that could help for review: https://forums.unrealengine.com/t/load-assets-from-mounted-pak-files

There is also "UnrealPak.exe" for the use case.