Helical milling with a diagonal repeat ?

Glad to hear you're making good progress markjacks

As you've probably noticed, the <tunepin> subroutine uses the values, whereas the <hole> subroutine uses named GLOBAL variables.
A named global variable has an underscore before it's name as in #<_safeZ>, and once defined (#<_safeZ> = 5.0) can be used in any subroutine.
A named LOCAL variable such as #<Feed> (no underscore) can’t be accessed outside of its subroutine - that way you can
use the same parameter name with a different value in different subroutines.

I like to use lots of white space in my G-code too, because it makes it easier for me to read (6 or so months) later on. Because the interpreter ignores
white space, it makes good sense for us humans to take advantage of this.
is a lot easier to read than
I have my text editor set to show a right margin at 80 characters & tabs set to 4 spaces
& lately I have set it to replace tabs with spaces, so when using a different editor, things still align OK.

Playing with white space a bit, adding the P parameter, plus sexy entry an exit maneuvers (improves work finish) your code might look like I prefer my comments off to the right so the flow of the code isn't interrupted.
Here is an over-commented example, using a line-feed to separate the sections Hope this helps.
Regards to all
Noel