2019 now, and I am thinking of running DG for a Pathfinder 1 group. I like your conversion. But I am also adding this SQ I made up for my home brew. What do you think? You still out there?
Covert Creature (Ex): Covert Creatures are natural spies and have a unique set of affects because of this nature. They are not subject to detection spells, though anything they carry can be detected as usual, and thus do not detect as any alignment (TN), Undead, magical and are generally immune to any effect or ability that reads auras or detects natures by divination. Any spells or spell-like abilities a Covert Creature has are automatically treated at though the feat Conceal Spell (Ultimate Intrigue) accompanied any casting, there is no level increase requirement for this ability when cast by a Covert Creature. Advanced Covert Creatures (Over 10HD+) can choose to naturally reflect spells that detect alignment, always reading as being the same alignment as the creature/person casting the detection spell.
I the posted one above was yours... 
