We are using multi partitioned assets with date partition and a static partition. I want the update the start date so that we only ever have about 2 weeks worth of partitions just to reduce noise in the UI. Would there be an issue with changing the start date for these partitions or would things keep working fine.

Hey Pablo--things should continue to work fine if you change the start date. When multipartitioned materialization events occur, Dagster stores the partition key per dimension. So even if you change the start date, Dagster will still be able populate history for the existent keys in the UI.