One of my knobs was flaking its top layer off so I designed replacements. Each knob is 2 parts held together with compression. No support material needed during print. I suspect they will work for other Weber models.
Printed on both a Prusa MK3 and XL with Overature PETG.

If you are starting from the STL, in your slicer add fuzzy skin to the outside of the knob for extra grip, and I think it looks better.