It turns out some games are able to export and reimport textures by adding them to the UPKInfo files. However, I've also noticed that whitelisting certain games does not work. The games themselves do work with the tools if you replace the header during export/import and then change it back to the original game's header via hex.
Example: Hunted: The Demon's Forge's header is C183 2A9E C500 0000, whitelisting its version number (709) will not allow you to export or reimport textures from its UPKs and give you a Bad Package Version error. However, hexing the header to that of XCom (C183 2A9E 4D03 3B00) will allow you to export/reimport textures perfectly fine, and the game will read them so long as you change the header back to the game's original.
Other games this method works with: Aliens: Colonial Marines, Dishonored, Remember Me, Thief (2014)
It turns out some games are able to export and reimport textures by adding them to the UPKInfo files. However, I've also noticed that whitelisting certain games does not work. The games themselves do work with the tools if you replace the header during export/import and then change it back to the original game's header via hex.
Example: Hunted: The Demon's Forge's header is C183 2A9E C500 0000, whitelisting its version number (709) will not allow you to export or reimport textures from its UPKs and give you a Bad Package Version error. However, hexing the header to that of XCom (C183 2A9E 4D03 3B00) will allow you to export/reimport textures perfectly fine, and the game will read them so long as you change the header back to the game's original.
Other games this method works with: Aliens: Colonial Marines, Dishonored, Remember Me, Thief (2014)