It seems to be working.  I saw one of my images already resized (looks better than before), and the options for choosing to display and to see at full-sized seem to be working.  I've also gone back through some of my gallery and edited the image setting on the larger images, even though most of them have not yet been converted.

Despite what I felt was an initial bad decision, you have responded quickly and adeptly.  Kudos to you and your team.

Dan among Den