Character Flaws

I do like a good dungeon crawl with mechanical hacking, slashing, and looting galore but what makes D&D shine above a board game such as Descent is the role playing. Spontaneous good spirited role play is lightning in bottle to force yet creates the most lasting fun memories. So how do we gently encourage meaningful role playing? I am thinking the carrot over the stick here for sure. The rules as written give the DM a very elegant mechanic to reward players called inspiration. What is badly designed per the rules is when to award it. So let us connect the dots here. Each character gets to pick a minor and unambiguous psychological flaw for their character. Just a small something that is fodder for the player to drive in game choices that the player would not otherwise have had a reason to make. Each time the player legit role plays that flaw they are awarded an inspiration token which contrary to the rules as written can accumulate. Your character sheet has this relatively huge box for flaws, which I tend to notice is blank more often than not, so lets put it use! This definitely needs some play testing and feedback though before I would declare this a recommended house rule.