Enable MeasureIt and vertex indices visibility:

Add a new object, name it attribute setter
, and add a new geonodes setup to it. Drag the object of choice from outliner to the node tree:

And apply this geonodes modifier.
💡 If you want to edit attributes of vertices, you can skip the above step and just duplicate my object
and rename it to attribute setter
Add shape keys, set the 2nd shape key to have full effect:

Now you can use the base shape key to easily find and select a vertex you want to modify, then move to the other shape key and assign the Vector values as vertex location:

Finally you can go back to your object my object
, and add a geonodes setup transferring that data:

You can apply that geonodes modifier, or leave it dynamically linking the data.