I thought I would share this experience with the new Defender plugin for those wondering to install it or not. After installing, I went through the setup and first scans. What caught my eye was that my site was blacklisted! Strange - I had not had any indication at all that there had been a problem, so I followed the great documentation on seeing why it was being flagged. After looking at the results, I realized what the cause was: by mistake, I had blocked access to several WP sub-directories by mistake and Google was unable to crawl them. I changed the robots.txt file and reran the scan and all was perfect!
I am still discovering the other features as I install Defender on all of my WP sites! Thanks for this super new plugin!