Case insensitive search using a flag rather than 'contains'

As per cube.js doc, we should use operator ‘contains’ for case-insensitive search. It works fine.
But if we look at SQL ‘contains’, it is defined as ‘to perform SQL Server full-text search on full-text indexed columns containing character-based data types.’ (which also is its literal meaning).
Ideally, want the logic and term to be similar. Currently, with ‘contains’, it gets confusing.