I literally searched everywhere and was not able to find it anywhere.
I know the old PC companion location is
C:\ProgramData\Sony Mobile\Update Engine\db
And then it moved to
C:\ProgramData\Sony Mobile\Update Engine\localstorage
And now since the software changed its name to Xperia Companion, I wasn't able to find any related location.
I know for a fact that the folders are now under the name Sony instead of Sony Mobile, since the install location was
C:\Program Files\Sony\Xperia Companion
And the old Sony PC Companion's install location was
C:\Program Files\Sony Mobile\
Any clue on the new firmwares location?