Etcher definitely supports all USB types, including 3.1, and actually, the faster, the better.
All in all, it’s extremely difficult for any software to damage hardware. In case your USB has already been broken and you have a warranty, I’m sure you can ask your local merchandiser for a product replacement.
In Balena, we are willing to help all Etcher users by supporting them and providing them with the right documentation to troubleshoot any issues. However, we have zero tolerance in any verbal, physical, written, or other abuse.
As a reminder, etcher is licensed under the Apache License 2.0. You can find more information about the Disclaimer of Warranty and the Limitation of Liability here: https://github.com/balena-io/etcher/blob/master/LICENSE.