Can we add a delay buffer on the clk capture path to reduce the setup slack value (i.e. I am trying to tweak with the launch clk arrival time so as to delay the data required time) when all attempts to reduce the setup slack are invain like resizing gates, buffer insertion, placement eco, and others.
Buffer addition to the capture clock path will definately help to improve the setup slack. But we need to be careful as it can violate hold at that point as we are delaying the capture clock. This methodology can be tried if the hold numbers are positive. Make sure that you add clock tree buffers to it rather than the normal delay buffers.