I have found that the best SEO practice for this case is below setting(Currently Version Mage 2.2, 2.3);
Use Categories Path for Product URL: YES
Use Canonical Link Meta Tag For Categories: NO (This is so that We don't get penalize for the duplicate content issues coming from same categories for the products)
Use Canonical Link Meta Tag For Products: Yes
Make sure you
set Create Permanent Redirect for Old URL
and Under Marketing>URL Rewrites> Set all products to have Redirect Type for: Permanent(301)
Short Concise URL to contain two or three keywords you are trying to rank/emphasize for the product - When uploading products.
Meta Title: 50~66 Character Letters
Skip Meta Keywords (Current year:2019)
Meta Descriptions 125~155 Character Letters
I would like to hear back from the community about the above setting as a best practice for SEO.