ID 234704 - CornerPin2D is slow processing motion blur with expression link to Roto PlanarTracker

Problem summary

CornerPin2D is slow to process motion blur when using expression
linked Roto node with PlanarTracker

Customer reported version
nuke.10.0v4

Customer reported platform
10.10

Steps to reproduce

SlowExpressionWithMotionBlur_TF_01.nk

1) View Merge2 with baked out CornerPin2D animation and motion blur
approx. 4.7 seconds to cache to viewer

2) View Merge3 expression linked CornerPin2D WITHOUT motion blur
less than 1 second to cache to viewer

3) View Merge1 expression linked CornerPin2D with motion blur 
approx. 10.6 seconds to cache to viewer

NOTE: if cache is not cleared between 1) and 3), Nuke will hang a bit on Mac (beachball) before rendering to viewer

Workaround
Unknown.

Reproduced by support
9.0v1-10.0v4

MacOS 10.10.5

Expected behaviour
No slower to use motion blur with an expression than a baked out version

Actual behaviour
Expression linked motion blur takes more than twice as long to render