[morningsam]

Looking through the options listed under "Non-Durable Settings", [1] I guess synchronous_commit = off fits the bill?

[1]: https://www.postgresql.org/docs/current/non-durability.html

[hardwaresofton]

Nope, Other commenter noted it:

https://www.postgresql.org/docs/current/runtime-config-wal.h...

Don't use synchronous_commit = off is durability ~= 0 (i.e. "I hope the write made it to disk")