Xilinx FPGAs - how to demote specific warnings to info or make them disappear?
I had this same problem for a long time.  Unfortunately there is no good way to change some warnings into info's or some errors into warnings.  My problem was that some warnings should have been errors!  Some of my FPGA's were generating 5000+ messages and there was no way to wade through them to see which ones were important or not.

In the end, I wrote a program that would read a Xilinx log file and reassign warnings/errors/infos depending on my custom settings.  Works great.  Too bad I can't make that program public.