Cheers, all.
Kadri, there were 30-something frames of 480 that I had to manually edit. There was no chopping of grass close to the camera, though, so that part was OK. The problem was the sun's disc, which was visible through single blades that passed over it, if no other blades were in front of them. It was fine when more than one blade passed over the disc of the sun. So, if there's more than one object in front of the sun then that might be something to keep in mind to make use of, instead of the render-heavy 'receive shadows from surfaces', in problematic scenes... don't know.
Hannes. A flat-scaled fractal or noise pattern enters the leaf shader's 'displacement function'. The amount of actual geometry
movement by that noise function is controlled by the displacement amplitude. This is varied over the frame range by shifting the noise pattern continually along whatever axis you choose the wind to be blowing.
If any of your scales in the noise function or amplitude are smaller than the object you're applying it to then you'll likely find stretching, tearing, exploding, etc.
Practice on a TG grass clump. Set
'number of blades' to '1' and get nice and close with the camera, you'll see exactly what's happening that way, over just two or three really quick test frames...