I saw that boolean columns are not supported by liquid clustering, too.  Why?  In any case:

By now there is an error that can get raised called DELTA_CLUSTERING_COLUMNS_DATATYPE_NOT_SUPPORTED.

There is also by now documentation of column datatypes that are supported by liquid clustering:

Clustering supports the following data types for clustering keys:

• Date
• Timestamp
• TimestampNTZ (requires Databricks Runtime 14.3 LTS or above)
• String
• Integer
• Long
• Short
• Float
• Double
• Decimal
• Byte