How to control fan out of an asynchrounous signal

Dear Fvm,

Thanks for your input, I am using Stratix II EP3SE110F78014 and the fan out is about 60000. The result show slack ~-0.7 and End Point TNS ~-4000.

By improving the TNS, I had tried to set the following

1) set the global signal to off in the assignment editor.

2) Increase the Effort level to Extra in the setting

3) Perform automatic asynchronous signal pipelining in the setting

And the result shows TNS ~-3000 in improvement. Is there anything that I can do to improve the TNS? I am following the guideline from the attached notes.

Thank for your patient and help.

Best regards

Kenny