Hi @sta_gas ,
Since data quality monitoring is in beta I'm quite sure they don't support foreign tables as of now (but they forgot to mentioned it in docs).
But more important question if they ever will be supported. For me data quality monitoring applies only to Delta Tables. According to docs description of how it works, we can see that they leverage delta properties to build this functionality. So I guess it won't work for foreign tables (at least there won't be the same feature parity).
"Databricks creates a background job that monitors tables for freshness and completeness. Databricks uses smart scanning to determine when to scan tables.
Freshness refers to how recently a table has been updated. Data quality monitoring analyzes the history of commits to a table and builds a per-table model to predict the time of the next commit. If a commit is unusually late, the table is marked as stale."