when you attempt to locate something in that grid keep in mid it will most likely be at some multiple of ten(10)
or what ever the vertical exaggeration of that profile is.
So you will not get the vertical distance directly it will be a multiple common vertical scales 2, 4, 5, 10, or 20
A trick I use to use in the past for this, draw your detail(s) at 1:1 horizontal and vertical.
Then make a block and insert it with x=1 and y= vertical scale