I thought with a small part you can attach it so it measures how much the bed moves to use it like a readout. I have seen pictures of this on small mills but I am not sure where the best place is. I saw a picture of a 2 inch one mounted to a taig.
My column and base is filled with epoxy+sand+lead shot, so its really sturdy/heavy/dampened there (I thought it was making too much noise when you cut things). I thought the best place was to make a threaded hole in the column, or to screw in a plate with a threaded hole in the column, so on the left or right side I can screw in a long adjustable arm with a dial indicator on the end.
I also thought to mount the whole thing to a piece of granite I have laying around, then put the dials on that. And maybe glue rubber under the granite. Then I can put an indicator that potentially reads the Z axis. Fortunately I have base comparators, so at least I have measuring parts covered.
The Z-axis is a little bit of trouble because if I tighten the screw down, it really almost gets rid of the vibration completely, like I can hear a huge difference in vibration when its set to the 'easy to move' tightness and the 'stuck' tightness. The x-y table waddles kind of, which is disappointing, but I think its ok, so when I use it I set a depth, tighten the z axis, then mill x-y, and I try to make holes on my precision drill press.
I thought maybe too it would be best to just buy a disposable B grade surface plate and attach the mill to it. They are kind of cheap. I think I am also going to try to fill the top cap on the column with epoxy sand, i think it makes a bit of noise too, so the column does not have any voids. I also got like quality brand name 3 and 4 flute end mills for it, and they make a world of difference compared to the really weird bits I got originally (I think they are for plastic, it was making horrible melty cuts, but the new ones work like a real milling machine)