Negative Scale and Dynamic Batching

Questions & Answers
1

I have 4 copies of a prefab in a scene with just a camera. Unity 5.2.0f3. Camera is perspective, prefab is mesh, material + texture.
A (0, 0, 0)
B (5, 0, 0)
C (0, 0, 10)
D (10, 0, 10)

First Question:
All 5 of them dynamically batch into a single draw call. If I set any of them to a negative scale on X, the batch is broken. Now, I would like for the negatively scaled asset to also batch, but of more concern to me is that if I set B or C this way, I get not 2 but 3 draw calls. Groups of opaque renderers should not have their batching interrupted like this. Can anyone shed some light on this?

Second Question:
If I have more than one of them with negative scale, those ones do not batch. Unity documentation states that multiple objects with non-uniform scale will batch with each other, so even if they don’t batch with the non-scaled ones, they should still batch with each other. Can anybody explain why this is the case?

2

There are lots of things that can prevent batching. According to the documentation,

Generally, objects should be using the
same transform scale.

3

October 2018 and back to this question, any solvets yet?