SRT export (SubRip) .srt format, vertical positioning, alignment
An SRT file (otherwise known as a SubRip Subtitle file) is a plain-text file that contains critical information regarding subtitles, including the start and end timecodes of your text, and the sequential number of subtitles.
It's important to note, an SRT file typically does not contain any information about the font type and font size - those are set on the playback software.
By default, SRT files will not retain vertical or horizontal positioning on export due to poor support for these attributes by different platforms.
If you need an SRT file with positioning info, go to the SRT settings tab in the export dialog and check the 'Export alignment' box.
This setting will write subtitles' horizontal alignment (left, center, right), as well as
vertical alignment (top, middle, bottom)