Cross-save is intended to allow someone to use an account they prefer to use (one that has more stuff or is further along int he game) to play on a different platform. For people that already have multiple accounts on different platforms, cross-save is less useful, as yes, it is selecting a single platform's save data to use on every platform. It is not a merge, a sharing of save data between accounts, or anything of the sort. What you're expecting out of it and what it is are two different things, sadly. In your specific circumstance and with your specific desire, cross-save won't be quite as useful to you, while in a different circumstance (such as the one you mentioned in which someone hasn't played on a platform before) it would be much more useful. So, yes, cross-save will work, but because it's not a merge or a sharing between multiple accounts, it just won't work for what you desire. You cannot mix and match what characters or what pieces of save data to enable with the cross-save. It's an all or nothing deal for the enabled account. If you enable your PS4 account as your cross-save enabled account, then the entirety of that save data will be available on all platforms. Anything you earned on the Xbox while playing with your Xbox characters will still be on those Xbox characters, and those characters will be tucked away in storage, along with all the related save data, including Collections, the Vault, etc (along with all the Y1 things you earned on those Xbox characters). None of your achievements or earnings from your Xbox characters will be available for your Playstation characters.