As I haven't figured out how spoiler tags work, and the warning in the thread title should be enough, here goes:
So, as a GM, how would you deal with PCs using clever ploys to kill a Nemesis out of combat, like Kylo did when bisecting old man Snoke? Assuming we use the rules and don't just rely completely on freeforming and GM fiat.
If we take the example at hand, I think its safe to assume that Kylo rolled pretty well on his deception check. If he rolled a bucket of Triumphs, I guess it could be fair to just let Kylo ice the old man (assuming a successful force check for move). However, wouldn't that in all fairness open up for the PCs to run afoul of such shenanigans with similar consequences? As a GM, I doubt I could get away with GM fiating my PCs to death without at least some chagrin, no matter how many Triumphs or Despairs are rolled.
Or, maybe just get a sneak attack in. With the "fine manipulation" control upgrade of Move, it seems fair to let Kylo make a combat check combined with move, and while there are no rules for sneak attacks, denying Snoke any Defense rating (except possibly armor, which does not look like an issue), and perhaps even Adversary (I see it as a simplification of Dodge, Sidestep etc) for that attack. Maybe even drop the difficulty a step. The thing is, even with all these advantages, one-shotting a Nemesis* is pretty damned hard, even with a fully modded lightsaber (Anakin's is mostlikely a EotE/AoR-level lightsaber). I think it's pretty fair to assume you'd need about 20+ damage or at least a +50 crit (if you roll really well) to pull it off. While definitely doable, it very much runs the risk of only severely wounding the Nemesis, leaving the PCs in the unheroic position of attacking and finishing off a severly wounded foe, whom they sucker punched first. Which risks feeling a tad... anticlimactic (in such a case, I'd rather have Snoke get away while his guards cover his retreat).
If we move away from the specific example of Kylo and Snoke, and instead imagine a lone PC confronted by the BBEG Nemesis in an abandoned warehouse (or other suitably atmospheric industrial locale). They banter a bit (the PC at a clear disadvantage if things should get physical, and both parties know it), and when the Nemesis gloats about the PC walking straight into his traps, the players smiles and rolls a successful deception check and has her PC reply "If I walked into a trap, then why are you standing exactly where I want you to?" and at that point the other PCs cut lines holding up the very heavy object that has been dangling precariously over the Nemesis. As the object (Anvil? Safe? Grand Piano? Do they have Grand Pianos in Star Wars? Let's call it a Space Grand Piano) Space Grand Piano comes crashing down, how would you rule it?
1. The PC rolled triumphs. Nemesis goes splat. (Possible downside: Might feel arbitrary.)
2. The Nemesis gets to roll... something to get out of the way to avoid or mitigate damage. (Possible downside: Players might feel cheated if they rolled well enough for their plan to succeed, but the Nemesis gets to make a roll to avoid the consequences, thereby doubling his defense (having already set the the difficulty for the deception check. Also see anticlimactic wounded villain above)
3. The PCs make an combat check for dropping the Space Grand Piano (will house rule and post stats at a later date). Combat system is used for calculating damage and other effects. (Possible downside: See anticlimactic wounded villain above. Also, a completely bungled roll in this situation might feel seriously anticlimactic, but hey, winning is sweeter when you've failed every step of the way to get there).
*I would be perfectly fine with statting out Snoke as a Rival, given his story relevance, or a weaker Nemesis, or even throwing out his listed stats and ruling him dead if the attack was at least fairly successful. But that'd be a little too GM Fiat-y for the discussion at hand.

