Caused by rBedb3b7a323a1. Using evaluate_fcurve_only_curve actually causes quite a bit of slowdown [6x] compared to bezier forward differencing [which was used prior to rBedb3b7a323a1]. But full fcurve evaluation is desired with Dynamic Interpolation Effects [Back/Elastic] since their min/max will not be captured with forward differencing. So now gain back speed [using bezier forward differencing] and only do the full fcurve evaluation for dynamic interpolation effects. Maniphest Tasks: T74927 Differential Revision: https://developer.blender.org/D7196