TSR-Experience (TSRE) is a box with mysterious content that aims to enrich your immersion and your involvement in the main narrative arc that encompasses each scenario. I think that only TS enthusiasts have already taken the time to read mission returns on the SpaceCowboys website, a sort of debriefing with your BOB instructor summarizing the mission accomplished in more detail, while preparing you for the next one.
Because TS scenarios do not have an imposed order, you can discover pieces of the main story in a timeline that belongs to you. "Experience" aims to embed and enrich the content of this blue cycle. You can discover more details about the environment where you live or customize your agents.
This last point leaves me pensive ... Can one envisage a system of progression of the heroes in the form of experience, of cosmetics as in the video games, or then in a narrative frame retracing multiple choice paths, like a book of which you are the hero ?
The SpaceCowboys' thinking around this "Experience" box is to allow players to appropriate the adventure of Time Travelers as they see fit.