Are Apex mission rewards tied to a specific SP character?

So i tried both MP and SP in the trial and opened a couple of loot boxes from the Apex missions i ran.

Whilst I'm waiting for full release Im running Apex missions from the app...now when the game launches im going to start a new character, the question is will i be able to access the loot boxes i acquire over the next few days or are they tied to the existing SP character?

Im assuming these reward boxes are put in a pool to be accessed by whatever SP character you want...but i want to check