When I work with heads that have a longer snout - especially the ones that have additional facial components that extend into the nose area like colour spots, freckles, etc - I find that masking them at higher angles (45-90 degrees) can be challenging because currently CA can only mask against the shape of the face. But when a part of the face protrudes outside the confines of the face it is starting to look weird at greater angles (see image)

Sometimes it is possible to cheat and warp stretch the face enough to cover the area you need but not always. It would be extremely helpful to be able to select more than one layer for the mask and use the union of those areas for masking.