Can I access expedition rewards on different saves?

Before I found out that I could use the expedition terminal to initiate expeditions in my main save, I was create new games for the sole purpose of competing expeditions. The rewards from these expeditions (not part of the current redux missions) aren’t accessible in my main save. Is there a way to merge save games? Seems like a reach but until we are given the opportunity to replay the first 10 expeditions or so (I’m guessing here), i fear the rewards will be lost to me. Thank you travelers.