I have a relatively small video of a screen recording of about 600kB in H.264 / VBR. Now I wanted to edit some unnecessary parts out. So I edited the clip and exported it, just to discover the size balloons up to 18MB. I used the "Share" button on the top left and an Apple Device 1080p preset.
The result is the same, for iMovie or FCP.
Is there an export method that preserves my original small video size or let me encode in VBR?