The toolbar names are not fixed. You can invent new toolbars in lib/ui/stdtoolbars.ui and add them to lib/ui/default.ui. Therefore you always need to construct the keyword in your patch.
This does not matter at all. A new keyword value pair will be added to $HOME/.session if a new toolbar is used, and will be loaded correctly when lyx is restarted. There is no cost of using a new keyword. As a matter of fact, the old keyword-value pair will be discarded if a toolbar is renamed or removed. Bo
