Since my last comment doesn't look like it's going to be approved, I'm reposting it without linkses...
I don't know if this is useful information, but on an iOS device, under /var/mobile/Containers/Data/Application/Avo/Library/Preferences/uk.co.playdeo.avo.plist, one of the Preferences listed in the plist is unity.cloud_userid, which is a string that is the same length as the Cache folder 1Emilis posted. (Except decapitalized and without dashes. There are actually a couple different strings I noticed in the prefs that have the same length, so I don't know which corresponds.) However, every device I put this on has a different string. I tried changing the folder name to match this setting in the plist (with capitalization & dashes to match the other), but it didn't make any difference. I put my cache file in /var/mobile/Library/OnDemandResources/AssetPacks/4E1D2DF3-2456-4215-A3D0-CCF0C658172E, as directed in the Internet Archive page-- and I assume that is the right place for it. I think that one thing we must be missing is the actual save data information for Avo that would tell it that it's already downloaded the episodes, probably inside that uk.co.playdeo.avo.plist I mentioned, or maybe one of the .jsons that gets generated. I assume whatever's necessary is somewhere in /var/mobile/Containers/Data/Application/Avo.