Thank you, and no need for apologies! I can see how this could be confusing.
The intent is that when you roll to face a risk, you might roll multiple dice. By default, you’re rolling a die from one of your skillsets (or a d4 if hindered by some disadvantage), but you might also roll dice from “help.” You only use the result of the highest die to determine how things go, so usually, more dice means better odds of avoiding risk.
The stress die mucks with that “usually.” Technically, it’s “help” — you can include it in a roll to improve your chances of a high result, avoiding a disaster (1-2) or setback (3-4). But if your stress die is higher than any other dice you rolled (like your one from your skillset), you get a stress effect. This is a trade-off: You’re likely trading one risk (whatever you were rolling to avoid, like accidentally depressurizing the cargo bay) for another (like alerting an alien to your position when you cry out in surprise) .
When that happens, you don’t have to roll the stress die again on that table on the back page; you just consult the number you just rolled. The way the table is written, the higher the result, the more intrusive the stress effect should be. That way, if you take a chance on the stress die and still roll poorly, you don’t get hit with double the misfortune. (And only rolling once just makes it go quicker.)
Hope this helps! Let me know if you have any more questions about this or anything else.