that explains some consequences turning off full_page_writes. If I correctly understood, turning off full_page_writes with BLCKSZ set to 4kB can reduce
significantly the amount of produced WAL, but you cannot be sure that you are completely safe with a PostgreSQL page that can be completely contained
in a 4kB file system page, though modern ones are less vulnerable to partial writes.
In the article, Tomas focus the attention on the fact that most of full page writes happens right after a checkpoint: a proper tuning of checkpoint can help
reducing the amount of writes on the storage, continuing to safely keep full_page_writes enabled.