With the new ability to study frame data, I confirmed the phenomena of lurching exists in general for all VRs and directions. In most cases the speed difference of the lurch is not clearly noticeable, but it is rarely zero. I confirmed that the speed of lurching in a given walking direction is always equal to the speed of dash canceling in the same direction. Walking skates are equal to the speed of dash cancel skates, minus a frame of deceleration.
My (not yet published) frame and speed data also reminded me of a phenomena I had forgotten. It is a simplification to state that holding crouch changes your walking speed to the forward walking speed. More precisely, holding crouch mirrors your back directions to your forward directions for walking, crouching, and skating. Back walking speed becomes the forward walking speed, but side and diagonal walking speeds can be slightly different (usually still similar to the forward walking speed). The side and diagonal multipliers for fastwalking appear to be global on a VR.
Speed data revealed a fourth fundamental type of walk speedup which I will call Boosting. To use it just keep walking in the same direction for a very long time. If you keep walking a VR will keep accelerating very slowly forever. This is likely a glitch. The amount of acceleration leak varies by direction and VR, but to give a typical example, after walking across a whole stage your walking speed could be comparable to dashing speed. Boosting can be done invisibly but the moment you let go of the direction you will rapidly lose all your boost. Boosting can stack with fastwalking, dash cancels, and 'new' rowing as long as it is performed first.