AutoInstancing and per instance random

Hey.Sorry for my English )
I am working on a stylized grass / plant setup for a 2D game.
I need plants to have bend / rotate to have rotation animation. Each in its own random phase of rotation.
I also need a plant response to the player.
Plants must be instances and use 1 drow call.

Final setup looks like this, but I have a couple more questions:

At the test level, there are about a hundred blueprints of plants.
I made the rotation through the shader using RotateAboutAxis, Sine function and WorldPositionOffset.
The reaction to the player is implemented in blueprints: when the player overlap the plant, a timeline animation is launched in the plat blueprint.
Everything worked fine, AutoInstancing system converted my static meshes blueprints to instances and i have 1 draw call for all plants.

But all plants rotated in one phase. And this phase need to be randomed. I have to add a random number to the sine function in shader (with which I did the rotation).

I thought we also have a shader node PerInstanceRandom and we have instances created by the engine. They definitely should work together. But unfortunately per instance random does not work with AutoInstancing.
Is this a bug or features of the functions of autoinstance and randomization?
In fact, I suspect that PerInstanceRandom necessarily requires an InstancedStaticMeshComponent in instanced actor blueprint.

Next for randomize the rotation phase I I tried to use the material parameter, which on each plant instance was set randomly through DynamicMaterialInstance in the construction script.

Rotations were randomized, but In this case I had a separate drow call for each palnt. Autoinstance did not work. As I suppose, this was due to the fact that each plant created its own instance of the material with the phase shift parameter. (If I’m wrong, please write).

Having not found a better solution, I returned to the first setup and instead of using PerInstanceRandom I used ObjectPositionWS -sum of x and y positions for sin phase offset.
I do not think that this is the best option for randomizing instances.

Final questions:
Please tell me if there are better solutions in my conditions?
Is it possible to set a random in shader level for AutoInstanced object not through a world position?
Using DynamicMaterialInstance disable AutoInstancing ?

I tried to make all the plants in one bluprient using InstancedStaticMesh.
I received 1 draw call, but for the reaction of plants to the character, I need to know the instance index with which the character interacts. I did not find this function in blueprints. Can someone know the solution to such a setup through InstancedStaticMesh?

Apologies for the necro post, but we have this same problem. It would be very useful if PerInstanceRandom produced a usable value under autoinstancing.

Alternatively, if an Actor ID of some kind were available in the shader it could serve a similar purpose (and more) for the autoinstancing path.

I’m sure the PerInstanceRandom value is just a hash of the seed with the instance index, which would be unstable under autoinstancing if it were provided as-is, but nevertheless an opt-in feature to add slight overhead to the instance data stream for this purpose would be worth it IMO.

We went as far as collecting every individual static mesh in the level into Hierarchical Instanced Static Mesh buckets in order to be able to use PerInstanceRandom, but to my surprise that was substantially slower than autoinstancing so it was abandoned.

Note to OP: In a custom node, Parameters.PrimitiveId can be input to a hash function to accomplish this.