No. Cross Save isn't really merging accounts, it just makes one account able to be played on different platforms. So if you want to use your beta emblems you'll need to make your playstation account your main which will overwrite your pc account progress and allow you to play your playstation save on your pc. I believe the overwritten save is still stored somewhere so if you disable cross save (after the mandatory 90 day lockout) you can go back to what you have on your pc save. I hope that makes sense. In short no, there is no way to merge accounts.