You're on to something, Steve. I implemented something similar at a past employer, and we were able to correlate consistency of development discussions with high engagement scores. I took the same approach to my next employer and replicated the engagement improvements. The key was in the tools and resources we developed for managers. I'd be happy to share more if you want to discuss. 

A lot of organizations struggle with the same issue, once performance processes feel heavy or formal, people tune out. What usually works better is a very simple, repeatable conversation framework that focuses on development rather than evaluation. Some teams use a light tool just to keep those check-ins organized without adding complexity.

Took the attached IDP (Individualized Improvement Plan) plan found on the web and attempted it with our workforce (about 35 front line people at time). Great thought, but I felt some EE's approached just as what their manager would want to see. It was designed for EE's to drive the conversation, but few (if any), really did. Also, many ended up with "read this book with your manager" which I think put too much emphasis on the manager's role in the process. Something like this, I think can be a good idea, but I think it relies upon the actual interest an EE and ER has in development and felt very supplemental/unimportant when other performance was not at it's best.