Actually, I had a go, I tried combinations of Gimbal, Normal, Local and Global with Active Element, Median Point, Individual Origins and Bounding Box Centre... none are giving me the even extrusion result I'm after (on the attached .blend called "Uneven.blend" - just removed the .txt).

So, that doesn't work. Keen to see what others come up with.

ETA: by the way, I tested this using [S] - scale - on the highlighted vertices.

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks