In Solid 1.0, effects are synchronous, but this will change in 2.0 where effects will be scheduled with microtasks (awesome!), and is also the direction the TC39 Signals proposal is going in.

Currently some logic in InstancedMesh relies on the synchronous nature of Solid effects. See how #updateSingleInstanceOnly is used within effects currently:

This will break if effects are not synchronous. F.e. if effects are async (microtask scheduled) if you use setIntanceRotation, and then set the positions attribute in the same tick, the next update will fail to update all positions because #allMatricesNeedUpdate will not have been set to true.

We need to update this logic so that

• if one of the attributes is set (f.e. positions) in the current tick, then the next update must always update all matrices
• if an instance setter (f.e. setInstancePosition) is used in the current tick, then the next update must update a single matrix
• if both of them are used in the current tick, always update all matrices

cc @keywizzle