Can´t set indexing_threshold to 0 for bulk upload

I'm trying to bulk upload 4.5M points using qdrant but have been strugling with the ingestion time. I tried to run it in memory to speed up, tried to use the upload_collection as suggested in the points docs. But it seems that the main problem is not being able to set the indexing_threshold to 0 as sugested in the bulk upload docs

Current Behavior

On v1.9.0 creating a new collection with the optimizers_config setting the indexing_threshold to 0, updating the collection to set the indexing_threshold to 0 seems to have no effect as the snippet below provide example

Steps to Reproduce

from qdrant_client import QdrantClient


client = QdrantClient(":memory:", prefer_grpc=True)
if not client.collection_exists("title_vectors_simple"):
    client.create_collection(
        collection_name="title_vectors_simple",
        vectors_config=VectorParams(size=384, distance=Distance.COSINE),
        optimizers_config=OptimizersConfigDiff(
            indexing_threshold=0,
        ),
        shard_number=1,
        quantization_config=ScalarQuantization(
            scalar=ScalarQuantizationConfig(
                type=ScalarType.INT8,
                quantile=0.99,
                always_ram=True,
            ),
        ),
    )

# Returns False
client.update_collection(
    collection_name="title_vectors_simple",
    optimizers_config=OptimizersConfigDiff(
        indexing_threshold=0,
    ),
)

print(client.get_collection("title_vectors_simple"))

Output:

status=<CollectionStatus.GREEN: 'green'> optimizer_status=<OptimizersStatusOneOf.OK: 'ok'> vectors_count=None indexed_vectors_count=0 points_count=0 segments_count=1 config=CollectionConfig(params=CollectionParams(vectors=VectorParams(size=384, distance=<Distance.COSINE: 'Cosine'>, hnsw_config=None, quantization_config=None, on_disk=None, datatype=None), shard_number=None, sharding_method=None, replication_factor=None, write_consistency_factor=None, read_fan_out_factor=None, on_disk_payload=None, sparse_vectors=None), hnsw_config=HnswConfig(m=16, ef_construct=100, full_scan_threshold=10000, max_indexing_threads=0, on_disk=None, payload_m=None), optimizer_config=OptimizersConfig(deleted_threshold=0.2, vacuum_min_vector_number=1000, default_segment_number=0, max_segment_size=None, memmap_threshold=None, **indexing_threshold**=20000, flush_interval_sec=5, max_optimization_threads=1), wal_config=WalConfig(wal_capacity_mb=32, wal_segments_ahead=0), quantization_config=None) payload_schema={}

Expected Behavior

I expected that creating the collection or updating it would set the initial parameters but most of my configurations in the creation of the collection were simply ignored

Start with the QdrantClient create_collection and update_collection entry points in the reproduction, using the v1.9.0 behavior shown in the issue. Verify why OptimizersConfigDiff(indexing_threshold=0) is ignored and confirm completion when the returned collection configuration reports indexing_threshold=0 for both creation and update.