I don't have a trinity nand image to share, however when reading through xebuild documentation I found this:
Devkit image building:
This feature is currently considered Beta/Work In Progress.
A new image target type was added, "-t devkit" which builds 64M flash images for devkits. Currently untested,
building with a 00 filled CPU key will create a zeropaired devkit image that may allow one to boot a software
bricked devkit that one does not know the CPU key for and recover it to an operational state. By powering on
the console with such an image present, with a recovery DVD in the drive, the recovery software should be able
to create a new keyvault, re-pair the DVD drive to the new keyvault, and allow normal operation once complete.
Normal devkit image building when one does know their CPU key and thus has security files and keyvault should
work as expected.
Building devkit for glitch/jtag is also possible using the standard -t glitch/jtag methods. Sample ini
have been provided with this release, but will not work unless patches and files are supplied. Note that devkit
is not our focus, but was relatively easy and straight forward option to supply for those that wish to make
use of it.
So theoretically you could build a zeropaired image and flash it on the kit and then boot a disc based recovery, I guess?
I am not sure if you tried this already, but if you did not then maybe give it a try