I’m planning on doing a short write up and posting to Svelte so hopefully we can all learn from each other. Edit posted here: Converted a project to Svelte. AMA
Did you automate any of it or all by hand?
All by hand 
. Porting code and some refactoring moved pretty quickly. Agree with the statement above: many of the principals are so similar that this was not as large of a task as you would think
Were you using packages like Autoform and Simpleschema beforehand?
No. My forms are pretty simple and with svelte the code is super straightforward. I considered introducing Simpleschema but it felt a little bloated. I’m using check but may move to something like ajv in the future.