xhc-hb04.tcl script ( pendant request / question / script improvement?? )

I've got a standard / common 18 button XHC-HB04 usb wired pendant.

It works great, but I've got a question {and I've been looking at the
github.com/LinuxCNC/linuxcnc/blob/master.../hallib/xhc-hb04.tcl
with a view of trying to modify it.... but I've not got a clue.... {not unusual!}

basically I am setting up the pendant to use with a number of different configurations. Most are easy as they align with the available axis / sequence of axis being used

eg: x,y,z {router}, x,y,z,a {mill + plasma}

but I've come unstuck with a lathe..... x and y axis only.... no "y".

I know the settings are done with "coords = x y z a"

# coords: specify upto 4 letters from set {x y z a b c u v w}
# coords: switch labels are xyza but any unique 4 letters
# from the set {xyxabcuvw) can be used (if the coord exists)
#optional, 4 max, default: x y z a

any chance on maybe being able to change the code to allow for maybe an "0" {or something else} to be inserted which would just be ignored..... that way
"coords = x 0 z"
would align with the switch position + markings

yup I know I could just use the hal component
linuxcnc.org/docs/html/man/man1/xhc-hb04.1.html
withbut thought it would be easier {more self contained} to use the xhc-hb04.tcl script to do it than linking all the xhc-hb04 pins to halui pins for a lathe.... but then I guess there aren't that many anyway to link

thanks in advance

Rob