I just received a warranty replacement for my 13v4.
And the keyboard has changed again.
New /sys/class/dmi/id/modalias
dmi:bvncoreboot:bvrPureBoot-Release-15.1:bd01/01/1970:svnPurism:pnlibrem_13v4:pvr4.0:rvnPurism:rnlibrem_13v4:rvr4.0:cvnPurism:ct9:cvr:
Note the “_” after rnlibrem
I changed my /sys/class/dmi/id/modalias to
evdev:atkbd:dmi:bvn*:bvr*:bd*:svnPurism:pnlibrem_13v4*
KEYBOARD_KEY_56=backslash