Recommended settings

Sorry for the delay, the recommended settings are the defaults. The delete originals option ONLY comes into play when using the conversion operations, since they create new files with a new file extension. Optimization happens in-place, so there’s no originals to worry about.

Even if you ARE using the conversion options, I wouldn’t personally enable Delete Originals unless you’re running low on storage resources (or believe that is going to be a concern down the road).

Last, but not least, many people like the lossy operations, and they are quite good. I don’t run any image-heavy sites, so I generally just stick with lossless compression myself.