@smokey I'm not sure the length of the season was the problem for character development in Riverdale. Season 1 was fun, but I think with the hindsight of the next two seasons it's clear that the problems with the writing were just becuase the writing isnt' very good, not because the season was too short or anything else. They never got any better about character development or sacrificing character motivation at the altar of "what the plot needs this week."

But with Agents of SHIELD, I think there are two things working in its favor: 1) We already know these characters (as you point out), so there's less need for development, and when they do it they can build on what's come before, and 2) The writing is good and the writers are good at doing a lot of character work with even just a few short scenes.

Also, it's a show that seems to care more about character development in general. That episode you mention was almost entirely character development with only minimal plot advancement but it didn't feel like it bogged the show down at all. Also because the rest of the season has been moving so quickly it felt like a nice short break to have an episode that was almost entirely character driven rather than plot driven.