This has probably been done before, if so please send a link.

So when DJ gets Finn and Rose through the security of Snoke's ship, how would you translate that?

Some extra uncanceled success is a definite in my interpretation. I would think however that the First Order security technician saw a little 'blimp' on their screen.

I would say this interprets into some (maybe only 1) disadvantage? Maybe the actual security tech, docking authority doesn't notice right away, but maybe someone else like a programmer does? I don't know. They get discovered down the line anyway (BB-8 failing Stealth?)

I guess the real question is, is the roll straight success and advantage? The security docking tech certainly notices something, but ignores it.

What follows is just my interpretation / opinion:

I would say, only one success is needed. Interpreting the scene from the movies, with the ruleset in mind, there should be one (1) uncancelled success, there could be more. The amount would likely be unimportant, as long as there is one.

Also, this wasn't a straight skill-versus-difficulty roll in my train of thought. I'd surmise this was an opposed skill check of Computers versus Perception or Mechanics. Then there are a couple of ways to think up the roll results. One way of interpreting the scene, is to have the Shield Tech adding his skill in the opposed roll, and the roll resulting in one or more net advantages . The Tech sees something, but ignores this (advantage used). The other way of interpreting this, might be to have the roll result in one or more successes with, indeed, a threat. It becomes unclear, however, how this would result in the Tech ignoring this. Perhaps by having the Tech see the glitch in the shields ( threat ), and then flipping a Destiny Point to have the Tech not report this in (story manipulation).

I'm confident they failed their group Stealth check, but probably with Advantages and a Despair. The Advantages translated into BB-9E not being able to act right away, but the Despair was that he got a good enough look at Finn that he was able to get Phasma's attention. So the players probably knew they had a limited amount of time to act before the jig was up, and they were probably reasonably confident that the response was going to be overwhelming.

Excellent interpretations, thank you.

My take: DJ didn't roll.

DJ was an NPC, getting onto Snoke's ship was his purpose. The whole misadventure "side quest" on Kanto Bight was to get a Slicer, which the players were able to, and that was the player challenge needed to get onto Snoke's ship. So by having a Slicer, the players didn't need to make a check, it just was an assumed success. If the players party included a PC Slicer they could have made a very difficult check themselves and avoided the side quest.

After that I agree with Captain Raspberry about a failed group Stealth check.