Adding an identity column to the CI key will avoid dups similarly to the internal uniqueifier value. Be sure to choose a data type like bigint to avoid overflow. 

If the source data contains greater time precision than you currently store, consider using `datetime2(7)` to reduce collisions and provide more accuracy.

When you only care about the first event for a given time, use `ROW_NUMBER() OVER(PARTITION BY time ORDER BY time, identity_column)` and select row number 1.