I downloaded a package Lua Dev that adds more complete syntax highlighting for Lua.
By default, both Lua and Lua Dev are selected for .lua files (with Lua being primary and only one in effect). I went into the menu and selected Lua Dev as the default Syntax to open with this file type. This creates a Lua.sublime-settings file, not a Lua Dev.sublime-settings file it works until I restart Sublime, then it is back to Lua/Lua Dev but Lua being the primary.
When I delete it and create a Lua Dev.sublime-settings file nothing changes. It still defaults to Lua. If I change it to Plain Text as the default it creates a Plain Text.sublime-settings and seems to default to that.
I confirmed in the Lua.tmLanguage file that is included in the plugin the string name is "Lua Dev" and not Lua.
No matter what I do, I cannot get Lua Dev to be the primary and preferably only Syntax that loads for .lua files.