Switching to DISTSTYLE KEY(id) could improve performance by colocating data with the same id on the same node, reducing data shuffling during query execution. However, before making the change, confirm that id has a uniform distribution to avoid creating new skews.

Additionally, consider:

1. Segmenting Large Columns: Move colA to a separate table if it's not always required, joining only when necessary.
2. Optimizing IN Clauses: Use temporary tables to store the list of IDs and join against them, which is often faster than long IN lists.
3. Cluster Resize: If storage usage is high, consider resizing the cluster to enhance performance.

Test each approach in a non-production environment to validate improvements.