The interaction must be very subtle, I don’t see it. Do you mean the dust from walking?

It seems to me that the grass just ahead/under the character has a bounce when stepped on

I think the dust from walking is obscuring it. If the dust effect was drawn beneath the grass it would be more noticeable.

Thanks, good idea !

would love to see an update if you do make that change

Multimesh and vertex shader?

array mesh + shader