You're right, that mode provides process crash recovery, not power-loss durability. The benchmark compares it against fjall’s equivalent buffered-WAL mode.
Agreed. Good design is when the things do what you expect them to do without reading the manual, don't reuse wording with other meaning in the wrong way. That way if you do encounter nee wording, you know you should read the manual.
If your system has a reasonable tolerance for power failure (multi-az multi-cloud), this can provide much better throughput