For the last eight months, David Cogen has been living a double life. By day: a YouTuber and creator, the face of TheUnlockr, reviewing phones and testing ebikes and explaining how food smokers really work. By night and morning and every single other available moment in between: a coffee shop entrepreneur, working to get a Brooklyn spot called Coffee Check up and running. The whole thing started late last year and escalated quickly. He needed a new workspace after his previous lease ended,…