1. We will fix this on the next version.
2. The next version will allow you to use this second form (notice the 3rd parameter is 2):
editor.ExecutePlugin( "Snippets.dll", eePluginUserMessage, 2, "/FolderName/SnippetName" );
The separator character (in this case, ‘/’) must be used as the first character of the string.
‘/’ can be any single character. For instance, the following is also OK.
editor.ExecutePlugin( "Snippets.dll", eePluginUserMessage, 2, "|FolderName|SnippetName" );
You can still use the old form (3rd parameter is 1) to keep backward compatibility.