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NPCs randomly disappear from stations (but not docks if you're landed) to simulate personnel 'churn'. If you dock at one point & find a good NPC, don't expect them to remain there once you've docked at another point; leaving the zone will almost guarantee the NPC changearound*
The Level 3 smalltalk "Best Job Applicant" does not alter or create crew. As the marked person will exist in a save made directly before carrying out the smalltalk, savescumming can be used to gain access to the results without wasting a gift.
*Specialists tend to hang on to their stations for quite a while; however there is still no guarantee they'll be there when you get back..
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