I ordered the tool setter from Dash Made Woodworking. Hes on this forum and he has a cap you can use for flattening bits. Hope to have the full setup soon.
I have an ATC spindle, and use my tool setter to measure the offsets for the tool table.
For my wider tools, such as those with 2 or 3 carbide inserts, I temporarily change the touch off location of the tool setter plate in Masso so that the insert tips are centred on the plate.
I perform an auto tool zero for each insert, and make note of the recorded offset. I then average the offsets and manually record the value in the tool table. When done I reset the location of my tool setter.
If I were surfacing a spoil board, it probably would not be in a program that ran other tools with other operations, so I would not use the tool setter. I would just touch off the surface using my 0.025 mm metal shim and adjust my Z height accordingly for that occasional surfacing operation.