Can we export a track with blank leader?

I want to economize project file size by trimming silent sections of tracks, such as a vocal harmony track that starts about 40 seconds after the song starts. So I delete the first 40 secs of the track, ending up with a blank section before a clip of the harmony. I also delete the section after the harmony clip, up to the next harmony section. So the track appears as 40 secs of blank space, a clip, another blank space then another clip.

But when exporting such a selected track, Audacity adds silence only between the two harmony clips and not for the first 40 secs. Maybe I’m hoping for too much, but is it possible to export a selected track with a blank leader and have the blank leader section save as silence, preserving the structure of the track in the song?

There’s an option in Preferences.

When “Ignore blank space at the beginning:” is enabled, the blank space at the start is ignored (absent from the exported file).
When “Ignore blank space at the beginning:” is disabled, he blank space at the start is rendered into the exported file as silence.

Thank you for your kind help.