[Feature Request] Keeping Attachments like Fonts while encoding

I worked with FastFlix a lot and I have a lot of ass Subtitles in my movies and videos. They have extra Fonts attached to the File and I haven't found an option to just include attachments yet? Maybe there could be a button which would put an `-map 0:t -c:t copy`
for example at the end. Bc writing it again just to put the Fonts back takes a lot of extra time.