Runtime 18, including Spark 4.1, is no longer in Beta. You can start migrating now. Runtime 18 is available now only for classic compute. Serverless, or SQL warehouse, still using older runtimes. Once 18 is everywhere, we will be able to use identifiers and parameter makers everywhere.
https://databrickster.medium.com/databricks-news-2026-week-2-12-january-2026-to-18-january-2026-5d87...
https://www.youtube.com/watch?v=0LsC3l6twMw

My blog: https://databrickster.medium.com/