There was one minor MCU connection actually. The Dogs of Hell biker gang were in an episode of the 1st season of Agents of SHIELD, although I wouldn't fault anyone for suppressing the early part of that season from their memory.

Why can't any show have consistent time travel rules? Generally, changing something should either:
1. Create an alternative/branched universe where things moving forward are different, but nothing that has already happened is changed.
or 2. There are no branching timelines, therefore any change will affect the…

Yeah, SHIELD is definitely improving, and yesterday was one of their best so far, but when I watch Arrow the next day, it's like they are not in the same league at all.