Facial landmark detection not recognising unconventional eyebrow shapes

[Infundibulum]

Hi,
I have noticed that OpenFace is inaccurate when detecting facial landmarks in non-arched eyebrows (e.g. in the image below) and that it seems to expect the 10 brow landmarks to follow an arched shape. I was wondering if somewhere in the brow PDM there is a specification for the relationships between the points that the model tries to match in unseen data. If so, where in the code could I find and modify these expected interpoint relationships? Would a better way be to create a PDM from scratch using a dataset tailored to capture non-arched brow shapes in addition to the arched ones?