Can webvtt option be added as an alternative to Tx3g (mov_text)?

[neptune84x]

When packing Subler mkv files to the mp4 file, it adds internal and external subtitles (ass, srt) to the output in tx3g format in a nice way, taking into account the language codes.

As an alternative to this, can the webvtt option be added in addition to tx3g for smooth playback and simplicity? Subler already supports webvtt.

I wonder if it can only be added to bulk and automatic mode.

One reason; It causes situations that will confuse some players, including that of macOS, such as tx3g font size. But webvtt is just text and time code.

[galad87]

Subler uses AVFoundation to read .webvtt, and AVFoundation already provides the packets in a format that can be muxed to MP4. So there is no way to convert anything else to that format, it would require quite a bit of code to manually convert things.

Which players are confused?