Command Click on image does not add sample point onto adjustment layer curves graph

I'm sure that I have forgotten the howls of anguish and details when this all changed way back... There was also a keyboard shortcut to move through and select different points without using the mouse...

By @Stephen Marsh

The old traditional shortcuts for that still work, but I was puzzled because I couldn’t make them work consistently in an adjustment layer…it was working sometimes, but not other times. Then, after a while of playing around with it, I figured out the difference.

As it has been since Photoshop CS4 (2008) when adjustments became available as nondestructive adjustment layers, you can use the same -/+ and arrow/Shift+arrow key shortcuts that you could in the old modal dialog box. But — this is the key — the shortcuts work only when the targeted adjustment tool (TAT, but also called on-image adjustment tool) is enabled. As shown in the demo below, at first, the keys aren’t working, then after the TAT is enabled the keys start working.

Note that in the keystroke visual below the screen shot, the + shortcut is shown as = . That’s because typing + actually requires the Shift key, but because you don’t use the Shift key for this, it’s technically the = key, but + is easier to remember (as - /+, or previous point/next point).

Also, when a point is selected, it’s possible to click the Input or Output field, and nudge the selected value with the up/down arrow keys.

So once the TAT is enabled, it’s possible to select curve points and edit them using only the keyboard.

I'm sure that I have forgotten the howls of anguish and details when this all changed way back... There was also a keyboard shortcut to move through and select different points without using the mouse...

Yes that also works on the Mac side when one has the Eyedropper Tool already selected, then press the Cmd key and click with the Eydropper in the document area to place your curve points.

Still available on Win but with Eyedropper tool active, otherwise it will temporary switch to the Move tool.

@Mike_Gondek10189183 

Try using the following “On-image adjustment tool” with a single-click on the image to set the curve control point: