Setting BLCKSZ 4kB

Hi,

I am trying to solve WAL flooding due to FPWs.

What are the cons of setting BLCKSZ as 4kB?

When saw the results published on http://blog.coelho.net/database/2014/08/17/postgresql-page-size-for-SSD-2.html

4kB page is giving better performance in comparison to 8kB except when tested with 15kB row size.

Does turning off FPWs will be safe if BLCKSZ is set to 4kB given page size of file system is 4kB?

Thanks,

Sanyam Jain