I'm trying to make sure I understand how FEEDHOLD works. 

Sometimes when I"m cutting a sign, I'll run a second file with a smaller bit.  Even though I zero the Z before running the file, sometimes I need to stop the file, adjust the Z depth, and then resume. 
To do this, I should
1) Click FEEDHOLD
2) Move the Z axis to some piece of material surface that is at start, or Zero height.
3) Jog the Z axis down to the surface or deeper as needed (router still spinning)
4) Push the Z axis DRO to re-zero at the new corrected depth
5) Push Cycle Start and watch the  Z axis return to the point stored by the Feedhold click and resume cutting, but this time from the new Z Zero reference point.

Is this correct?  Is there an easier way?   Thinking out loud,  can I input a Gcode depth correction as an MDI and then resume?  And what is that proceed from box for? 

Lot of questions for someone from Washington State.

Thanks in advance

WayneC
Mach 3 on an upgraded Shopbot with Ascension controller. 

You could feedhold and move the Z clear then enter a new depth in the DRO for the Z, eg if your code says to cut a -0.5 but you find its only cutting at -0.3 then you can enter that dimension into the DRO and it will not go down a further -0.2 when you resume.

 Not sure what you are meaning by the"proceed from box" if its the Run From Here button then that is meant for when you have stopped the code and want to start at a certain spot. You clcik on the code windo and scroll down to the line you want to start from, click Run From Here and it will then scroll down to that line in the code and pop up a prep move box. If the move is correct (ie safe) you clcik ok and it will go to there, you then press start and it will continue with the code.
Hood

If you look further down the main page of posts, you will find a post on just this subject last week or so ago.

There the problem was thickness of workpiece - but it comes to the same thing.

Hood - I found the torch height control you were on about - it is on Config/Mill Options.

Did you find the FREEHOLD was the best way to acheive Z height adjustments, or is there a better way?

Steve