I try to make sense of most of the knacks made for the Fire Eaters. There is a lot of knacks that keep their standard effects but get the bonus from Gahad. I don't see why there is a knack for that because every action tests and effect tests get this bonus just by the standard rules. Unless...
a) the knack allows the bonus to be applied on rolls not intended to address the source of the gahad
or...
b) the knack allows the bonus to be applied again