Confused about async/sync dmenu mode

[kraftwerk28]

As far as I understand from rofi(1), by default rofi -dmenu doesn't wait until stdin EOF occurs, unless -sync flat provided.
Therefore,

(echo first; sleep 1; echo second) | rofi -dmenu

should launch rofi immediately, with one entry, first. Then after 1 second, second should be added to the list, right? But for me, it still waits 1 second and then launches rofi w/ two entries.

[DaveDavenport]

See the following setting:

	-async-pre-read [number]               Read several entries blocking before switching to async mode

[kraftwerk28]

That works, thank you!