First time I saw this trick was in a 1950s film called 'Escapade', but it was the reporter doing it, not being tricked by it.
Even for followers of the god of lies, that's seems a bit... uncouth.
I wonder what makes Col finally day "screw it" to being human presenting and walks around in base form but still goes around telling people he ain't a shapeshifter
So Col's secret is out (again), but he could easily out them as tricksters if they give him trouble. It seems in this word even accusing someone of that is enough to get them chased by a angry mob.
Alas, calling Mimics our for being tricksters would probably be ineffective since they can't use God's magic. The only reason Missy E. got away with it because she transformed Malo to look like he was using an illusion.
But Col's a nice enough person he won't send a mob on some innocent Mimics, even if they know his big secret. After all, he can sympathize with being chased by a mob, allegedly.