I'm using xfce4-panel version 4.11.0. Using documented Xfce methods, I am unable to increase the Application menu icons from the standard 16 pixels. This is a very serious impediment to visually impaired people.

In prior versions, I simply added a line to $HOME/.config/xfce4/xfconf/xfce-perchannel-xml/xsettings.xml such as

<property name="IconSizes" type="string" value="gtk-menu=24,24:gtk-button=24,24:panel-applications-menu=24,24:panel-directory-menu=24,24"/>

Now, that function no longer works but has apparently been taken over by gtkrc theming - see https://github.com/EasternHeart/heartlenv-shell/blob/master/docs/README.gtkrc-2.0

But that does not work either. Adding something like to my theme file merely breaks the theme.

style "applicationmenu-button"

    { 
        gtk-icon-sizes = "panel-applications-menu = 24,24"
    }
class "XfceApplicationsMenuPlugin"  style "applicationmenu-button"
widget "applicationmenu-button" style "applicationmenu-button"

Are we effectively left with hard-code 16 pixel menu icons, or is this a bug, or am I doing something wrong?