Hi!

You can create your own custom preset collection and set your icons like so (this image shows the old UI but the way to save presets is still the same one, tool panel > "floppy disk")

https://twitter.com/forgerapp/status/1088522237165166592?s=20

Hope this helps!

Hi!

You can save the startup material from the material parameters menu, press the floppy disk at the bottom-right corner. 
From that moment, new scenes should have the new “default material”.