Skyscraper
Adventurer
On condition that we take this as constructive criticism. The trap an RP-rewarding mechanic like Inspiration can fall into is that the DM is the judge of what constitutes 'good RP,' and thus who deserves the reward. It can turn the game into a 'please'/manipulate the DM exercise. Worst case, the players are like trained monkeys dancing for the DM's amusement. It's not a serious problem in 5e, because a DM who can handle 5e's Empowerment can be trusted to use such a system judiciously and to enhance the play experience, rather than 'abusing' it.
Ok. I'm with you I guess. I think that inspiration is not necessary to get players to RP and I don't like rewards being associated to that. That's just me. I agree that the downside can be avoided; I just don't see the upside to it.