How do I add Motion Blur to a VAT liquid sim in Unreal?

I’m trying to add motion blur to a VAT blood splatter in Unreal 5 with really weird results.
I can have motion with a MF_TransformVelocity but there’s a lot of horizontal lines and it’s very inconsistant.

2022-08-03 17_11_58-Window

2022-08-03 14_25_57-Window

I’ve tried the method explained in this thread but with no success:

I have a velocity texture exported that I’m not sure where to plug.

Sample the velocity texture at the same uv’s as the position texture, transorm from local to world, then previous frame is current frame - the result of that transform.

In VAT 3.0 Demo have working motion blur