Someone told me that another way to set path exception is by using set_case_analysis ?
Path exceptions modeling
In certain situations, path exceptions must be re-coded for ETMs, e.g., when there are multiple output delays on a port and one of the output delays has a multi-cycle path (MCP) through one pin internal to the block. Unless one successfully preserves that internal pin (which increases the size of the model) or duplicates the ports for that MCP, design teams must create and manage exceptions to achieve the same timing result as flat analysis.