Comment by bluGill
The question is how far can you break things down. Also what your job is (if you need to wash your hands before starting that matters)
If you are sewing a ballroom dress (that is any very large project) you probably need longer stretches to get it together. However you could take an individual piece and put in a few embroidery stitches.
Still it does feel like you get 2 minutes of work for your 15 minute break
This won't work for the sewing itself, but while Siri itself is still a hot mess, it can launch shortcuts into other apps. Aka can ask "Siri captains log" and I've configured my phone to launch voice recording so I can journal via voice. That isn't the same as actually sewing, but organizing my thoughts has value, especially if it's during time I otherwise would have burned.