Josh, I hope my following words do not insult you, but they may help you better visualize just what’s going on with George’s plugin.
Let’s call “longtext” a body of information that you want to define for readmore functionality. Immediately before longtext you must insert a [read more] tag. Then, immediately after longtext, you must insert a [/read] tag. When executed, the leading [read more] tag apparently seeks out the next following occurrence of the [/read] tag and then displays everything in between the tags as the desired longtext. Any such single implementation of the read more functionality can be visualized as a unique [read more]-[/read] instance. Because each instance is unique, you can have as many instances as you want on a page.
Note that the plugin’s apparent underlying logic results in the inability to NEST readmore instances. For that matter, I’m not sure why anyone would want to do that in the first place. Read more tags can NOT be nested.
I usually invoke HTML editing mode when inserting [read more] and [/read] tags because I find it easier to visualize just what will be displayed when the read more instance is initiated. Otherwise, you can just go ahead and enter the tags in visual editing mode.
On another note, the Read More button text is sensitive to what you place at the end of the label. For example, Read more >> will throw Read More Without Refresh into a tizzy. I use the following labels: Read more» and Read less« to insert >> and << at the end of those labels.
Good luck to you. I hope this helps.