Webvtt segments for HLS through elastic transcoder

Elastic Transcoder is creating segmented webvtt files for my HLS streams, with headers that look like this:

WEBVTT
X-TIMESTAMP-MAP=MPEGTS:0, LOCAL:00:00:00.000

Is there a way to configure Elastic Transcoder to change that to for example remove

1. Remove the LOCAL:00:00:00.000 portion entirely OR
2. Remove the space after the comma OR
3. Change the order portions of that line appear.

Finally, is this something Media Convert could handle, but not Elastic Transocder. If so, could you let me know. Thank you.