Implementing a tool changer, is ClassicLadder the way to go?

JetForMe wrote:

My tool changer won't be a carousel, but rather a row(s) of tools at the end of the router bed (I had the bed made extra long to accommodate this).

That sounds like a rack toolchanger, and that can be done entirely as a remapped G-code.

There is a sample config you can run, start LinuxCNC and choose:
sim->axis->remap->rack tool change
(You can run this on your live system or another PC, it doesn't try to move hardware and doesn't need hardware to run)

It needs a couple of lines in the INI file to specify the G-code subroutine to use when M6 is called:
github.com/LinuxCNC/linuxcnc/blob/master...cktoolchange.ini#L58
And then a G-code routine to calculate the correct position to move to based on the tool number:
github.com/LinuxCNC/linuxcnc/blob/master...ines/rack_change.ngc
The important part here is the use of M64 and M65 G-codes to set the values of the HAL pins that operate solenoids and brakes etc.
The main routine calls a sub-routine, you can find all the files here:
github.com/LinuxCNC/linuxcnc/tree/master...emap/rack-toolchange