Quote Originally Posted by Vvardenmarrn View Post
I'm not sure if I agree.
I played 1.0, therefore my product key came from before ARR, and before XIV was available on steam.
I have since bought a copy on steam too and regularly use this to play, however I did not register the steam copy to my account on the mog station.
Surely the steam copy of heavensward should work for me, as I already play through steam, but the non steam version should too? As my mog station account does not have a steam product key registered.
Steam copy of Heavensward will work for you.
Steam license key of Heavensward however will not.

You have to realize the key difference here. Actual software client has absolutely ZERO connection with the Steam client - you can launch FF14 without Steam at all.
What you're buying on Steam is a product key. You never used the Steam key with your account, you just used Steam to download the client.
Actual game is identical between Steam and a download elsewhere. What matters here are the product keys, which are separated into Steam and non-Steam ones.