To avoid spoilers, let's say I crafted the item, found the place, went there with Kuro in the party, but did not find the entity in question.  Instead there was the usual Balrog in the boss room, which my party beat like a red-headed stepchild.  Also cleared all other rooms in the dungeon, but nothing happened, and there are no ! search actions available to them, and Kuro will say nothing about it.  I spent a few days with the party in the dungeon, then went back to Aliron for a few days.  It looks like something did not work correctly, or there is some action needed that is not obvious.

0.13.1 of course

edit:  I went through the quest again, with the same result except Erebus Stones were the boss.  The only error message apart from the usual bunch of:

SCRIPT ERROR: Invalid get index 'L315L3  24' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

was this after the boss fight:

warning: make_slave_statreq_text() used 'is_at_location' code!