Editing Grasshopper UI Through Addon

I’m wondering if anyone has made, or seen an add-on that changes the grasshopper UI?
For example, I’m wondering if it’s possible to add buttons to the grasshopper tool bar:

I haven’t been able to come across any examples where this has been done.

Some of the attempts

also this thread from few minutes ago.

This is perfect, thanks for pointing me in the right direction!