Kewi or Siz or anyone that they give the nod for further maintenance is welcome to incorporate the changes and call it their own. Or scrap it all and add their own void storage method. I have no plans to maintain/support Possessions myself.
What this optional patch does:
The keyring is repurposed to void storage. If you have old keyring data it will even show up in void storage until you visit a void storage vendor.
Nothing else was changed, not even the version number. Any non-keyring behavior you're seeing in your current Possessions for 4.2 is unlikely to change with this.