Yes, some form of linear guide just to keep things fairly rigid but easily moved. A couple of round rails and bushes would do the same, just I had profile rails I bought cheap off eBay a lot of years ago, got 4 500m long rails and 4 trucks for under £10 delivered, I knew they would come in handy at some point. They are all used now, two of them on the height setters and two trucks and a rail chopped in half on the plasma Z.
Before I had the height setter I used to touch off the tools in the spindle and had the button to set the tool table in a similar manner as I use now.
The Beaver has a hyd drawbar, so just a press of a button and the tool is loose, release the button and it clamps instantly but the height setter is 10x quicker than that, no movements of X Y Z axis required
Hood