Alternatively, make a bunch of runs in VETERAN difficulty of any of the monsters listed, to speed the runs significantly and also avoid the higher level stuff @ the same time, increasing further the chances of having blueprints drop: [SPOILERS] List of Bosses that can drop blueprints
Highest drop rates are from monsters of “table C” but also have the lowest probability to drop blueprints. Highest blueprint drop probability is with “table A” but the blueprint you’re looking for has low odds. Still better then “table B”'s odds.
EDIT
Corrected the link, which was from the time before Crate’s Grim Dawn forum was hacked: old link no longer works because of the changes Crate did to the forums, which is why i removed it.