My guess is that the 'Licenced Debugger' used by Digilent, is a derivative of PICkit 3,
with firmware delivered from Microchip.
Look up Schematics for a Curiosity Board with PKOB 3 programmer/debugger,
and compare it with traces on the Digilent Board.
Note, that Curiosity Boards have been made in different revisions,
some with PKOB3 using PIC24 processor, and later with PKOB4 using a SAM processor.
PKOB3 is a stripped down PICkit 3, PKOB4 is a stripped down PICkit 4, similar to SNAP debugger.
The firmware is probably in a .jar file within MPLAB
There are many variations of PIC24FJ256, the next letters and digits are the most important part of the device identification.
My Discovery HPC board have PIC24FJ256GB106, same as is inside my PICkit 3.
Schematics for PICkit 3 is in PICkit 3 standalone Programmer Application v3.10,
Programmer Application User Guide: DS50002158A-page 65
It is also part of the installation package available in MPLAB Archive webpage.
Do you really need the Integrated Programmer and Debugger tool,
or could you get away with just 6 pins or pads connected to ICSP pins of the PIC32MX,
and use external PICkit 3 or PICkit 4 for programming and eventual debugging?
PIC32... devices use only 5 of those pins.