Still in the next big thing camp myself, also. Of course, there are the noted drawbacks, but for our use case: putting a library of UI components across a handful of app stacks (.NET, asp, Angular, etc) - Svelte is the solution.

We have faced the usual wild west frontier situations where nobody really had an answer for something we wanted to do, but we have worked out solutions without a huge deal of frustration.

And it's important to mention that the development and maintenance experience of Svelte is very pleasant.