Not sure how to break this to you other than just saying it:
This is insane.
Period.
Grass isn’t done with a single strand while wasting 99% of several textures (base color, normal, opacity, subsurface, roughness).
And then added with an equally insane amount of draw calls.
Not to mention, all your grass leafs would look nearly identical even with scaling.
Look up some tutorials on how to properly make grass.
Usually a good mesh is either 1m or .5m for the base layer, and several different clumps are merged in to randomize the look.
Ps: insanity aside, almost all “locked” sliders arent actually locked. Type the value manually.
Grass is probably actually locked. As it should be to prevent the engine from melting your computer…