With the (somewhat recent) functionality of "asymmetric sharding", i.e.:
- https://registry.terraform.io/providers/mongodb/mongodbatlas/latest/docs/guides/advanced-cluster-new-sharding-schema
- https://registry.terraform.io/providers/mongodb/mongodbatlas/latest/docs/resources/advanced_cluster

we are considering an architecture where we isolate specific collections or sets of collections on specific shards.

However we are also interested in using Atlas Search for these collections. We would like to use dedicated search nodes, but because of the above architecture, we would only need those search nodes on specific shards.

Because of this: for cost reasons, we would like the ability to scale search nodes for a shard independently, similar to how the electable nodes can be scaled independently.

That is, we would like to have:

shard-0: no search nodes
shard-1: no search nodes
shard-2: S40
or in the future something like:

shard-0: S10
shard-1: S10
shard-2: S40

depending on the workload on each shard.