Sadly, the idiots over on DLSite never updated even though Vhiel tried everything to get them to do so. Which unfortunatelly means that the only way to get the 4.0 version and the DLC is to double-dip and buy the game again either here or over on Steam, where they actually allowed Vhiel to update the version.
It's been a long time ago since you made that comment but I hope you were able to get a new version and enjoy the DLC of the game as it is very good.