If I buy Boundless on one platform, can I play on them all?
While all players will share the same universe, buying the game on PS4 will not enable you to play on PC, and vice versa
Your Boundless account is shared across all platforms and the forums. However your characters can only be used on the platform they were originally created with. This is ultimately a limitation we needed to accept to enable cross platform play between PC and PS4.
However, your alt-characters can still share permissions across your beacons as you can already do today.
If you have purchased Boundless on both platforms, you will have the option to use the same account on both platforms, but are equally free to use seperate accounts. Characters will be locked to the format in which they are created and are not able to be shared between platforms.