I agree that all of Bosco, Sybil and Granddaughter Stinky have been overdone a bit in the past seasons. That's the consequence of re-using the same characters and locations over and over again in all episodes in the season, unfortunately.
Luckily, it seems with season 3 they are handling things more carefully: different locations and characters to keep things interesting! And it seems that they are also careful not to overuse Flint Paper, just like Steve Purcell did in the comics: he is mentioned every once in a while, often enough to know who he is, but rarely enough not to get fed up with him. I'm extremely satisfied with the storytelling so far (although I've only played the first two episodes).