Beta Program Recommendations?

We just completed a 6-week closed beta with 50 users. We learned:

• Gobs of usability issues. As a result, we are redesigning parts of the app.
• User expectations within the context of the product experience = new feature ideas.
• Less than 50% of our beta users were not our target persona. We had easy access to these users, but their feedback yielded little value to us.
• Before you start, do some prep;
  -- interview scripts;
  -- a tool to record video interviews (we used Google Meet, it's free)
  -- use a feedback data app like Dovetail to organize and visualize data;
  -- set clear expectations with your users on time commitment;
  -- weekly communication with beta group on status