Burano for a few hours earlier morning

It's impossible to say. Earlier in the day, less people will be out and about.
Burano is definitely worth a trip. But if you want a really peaceful destination, stop en route at the cemetery island of San Michele - Diagilev and Stravinski are buried there.
Venice and its islands are my favourite places.. It is unfortunate that lots of other people go as well.
You have to make a judgement as to whether to not go to places you like because other people like them too.

I'd be surprised if you run into crowds at those times. I went to Burano around the middle of September 2023. I don't know which vaporetto I caught, but I'm not an early riser, so I know it was later than the times you're planning. When I got to Burano, it was nearly tourist-free, and it still wasn't crowded when I left.

This is pure speculation, but I think most visitors who want to see both islands head to Murano first.

I visited Burano several years ago, and wished I had spent more time wandering around. I loved it. And now that I've learned more about San Michele, I wish I had spent some time there, too.
Enjoy your time in the area!

We just went to Burano. So mid June. We got there in the morning but nothing like you are talking about. We left and went to Torcello about noon. By then it was noticeably more crowded. It wasn’t that crowded when we arrived which was probably 9:30 am.

I'd go to Burano either very early in the morning or late in the afternoon, to catch the best light for photos. I've never been on a crowded ferry that time of day during my early/late trips. But even if it is full, it doesn't matter, because Burano is worth it.

The last time I was in Venice in early May I caught the vaporetto to Burano around 8am and it wasn’t crowded. I got to Burano before 9 am and there was very few people around. Just some locals getting their day started. Burano is small enough that you can walk every street in less than an hour, so by the time more people started showing up I had some great photos. I stayed long enough to visit the lace museum that didn’t open until 10am, and I still didn’t have trouble getting on the vaporetto back to Venice. At that time, most tourists were still just arriving on Burano. As someone else mentioned, stop at the cemetery island for a nice peaceful walk.

Thanks all! I'm keeping Burano on my itinerary. I briefly thought about San Michele, as I love cemeteries, but decided it'd be wiser to head back to Venice for more exploring as my time there is limited.

I briefly thought about San Michele, as I love cemeteries

Unfortunately, photography is prohibited on San Michele - I understand it though - but I would have loved to add it to my list. You can photograph the island well from a distance. I always liked the subject with that one bridge in the foreground, and of course, I had to take a picture of it myself. https://www.flickr.com/photos/calabrones/40455135681/in/album-72177720314337177

If you're going early morning to take photos without people in them you might think about getting out one stop early at Mazzorbo if your vaporetto stops there. It's a small sleepy island attached to Burano by a bridge and if you walk along the wall towards Burano there's a door that leads to the Venissa winery and their garden. You can cut through their small fields toward Burano and cross Ponte Longo to reach Burano. And when you get there the people from your vaporetto will have landed and dispersed so you won't disembark with whatever crowd there is.

Hope you find your quiet piece of the lagoon,
=Tod