Months passed while I thought unity was randomly loading something the first time I pressed S at runtime in the editor... about shadergraphvariables

[Cyanilux]

That's odd. I do have some font-loading on the SGVariables side to calculate the width for the Get/Register Variable nodes, but that has nothing to do with the ExtraFeatures & shortcuts. And afaik it should only load once - I've seen no editor freezes on my end.

Anyway, I've tweaked the code a bit (moved the font loading into the ResizeNodeToFitText function where it's needed) which might help, so try removing the package & re-add it.

Ideally I would make the shortcuts only work inside the ShaderGraph tab (via using typeof(MaterialGraphEditWindow) in the ShortcutAttribute) which would avoid conflicts, however due to Unity's excessive use of internal those classes are inaccessible so the shortcuts need to be "global". That said, there is still a graphView != null check so these shortcuts won't do anything if a graph is not open.

If conflicts are common or the shortcuts aren't needed, they can be remapped/removed via Unity's Shortcuts window.