I jump between NLEs for my editing work, most frequently Avid Media Composer and Premiere Pro. After much thought, the top editing feature from Avid that I'd like to see in Premiere Pro is to have a single button (Shortcut) that loads whatever is in the source monitor into the timeline. This could be a clip but most useful would be with a sequence loaded into the source monitor. One click toggles between source/record in timeline.
I'm aware of the "Open in Source Monitor" and then "Open in timeline" combination and that this could potentially be invoked with a macro but with multiple sequences open in the timeline this can be confusing.
On Avid I use this function 100s of times a day, especially on longform when reversioning or dealing with producer notes.
This suggestion would make a LOT of die-hard Avid editors sit up and look.