After all these years…
I just discovered that when using “Use Scroll Wheel for Event Volumes and Fades” that actually includes Fades! Been using it forever for Volume only. Who knew?
With mouse hovering over a Selected Clip, holding down Shift while using the scrollwheel adjusts Fades. If the mouse/cursor is on the left half of the Clip, you adjust Fade-In; mouse/cursor on the right half of the Clip adjusts Fade-Out.
Way faster than finding the Fade Tab, at least for me. There are so many cool Key Commands in Nuendo. I would be willing to bet no single human knows/uses them all. No way.