Osnap has all options available through it’s corresponding named command line, and you can enable/disable/toggle it via the DisableOsnap command.
So this seems to enable you to create a completely custom Osnap toolbar with custom icons, if you don’t want to use the default text-based one… however, the most important thing which I want to add, which is a permanent “one shot” visible toolbar, is something I haven’t figured out how to access from a button. Does anyone know how to, for example, put “POnSrf” on a button?
Also, I can’t find the corresponding command line for SelectionFilter. Unlike the Osnap command, SelectionFilter only toggles the visibility of that toolbar, and not enable/disable/toggle (which again, is a consistency break in the Rhino UI). Does anyone know what the full options commands are named?