Touch off advice

I'm just setting up tool length touch off on the mill and am pondering ways to do it for multiple tools with a manual tool change.

I use a metal vacuum plate for my jobs and the part's aren't that complex, two sides at most but using a number of tools to finish the part.

Does anyone see a problem with me using the vacuum plate as the Z origin, so Z = 0 on the touch plate? I mainly cut Delrin so having the conductive vacuum plate as zero means it's easy to set tools after each manual change. I could then insert code for this to be done automatically after each manual tool change while still doing each side in one program.

Are there any glaring holes in my logic?

Jools

Addition - My mill is granite based so the frame isn't conductive so the sensor connection is naturally isolated until a tool touch occurs.

you are on the right way
touching to the bottom is best for you YOU THEN need no Tooltable Length as all are zero

make shure the tools in the G-code are only once to change if possible

you can automate this
by using simple ground and a E-clamp to the bit
then just
G91 ( relative mode for probing)
G38.2 Z-25 F100 ( trip plate on the way down)


or as a Button / Mcode / Key