Seperate Registration Codes for Multiple Platforms

[SevariaClarenille]

I realize that this may have been brought up before at some point or another--and if it has I apologize, I didn't see anything mentioned--but I think needing to buy the game and its expansions twice to play on both PC and PS4 is a little redundant.

Before anyone jumps down my throat about this, SE has allowed a "one-code/all platforms" policy in the past with Final Fantasy XI. Of course, you would need to have the base game installation disk for both platforms, but once an expansion had been purchased and registered to a service account, it was valid on all platforms (PS2/Xbox360/PC).

I mainly play on PC, and I own both expansions. Through certain circumstances, I also have a copy of the PS3 version of the game (upgraded for free to PS4) that I use whenever I feel like playing on a TV and relaxing on a couch instead of playing at a desk. My gripe is that I can't access anything beyond A Realm Reborn while on my PS4. I can't zone into newer areas, access 51+ dungeons, or level beyond Lv.50 even though I have jobs at Lv.70.

Is there a reason behind this particular lockout policy, or do I really need to pay for the expansions twice to gain access to what I should already have?