This is because the input is validated after every key press to make development easier. I didn't bother to improve it since most of the time the slider is used (you need to specify value range to make it show up though). To fix this the input would have to be validated after focus is lost.

So after pressing enter or clicking another box? I'd personally prefer this implementation. Apply changes when changes are complete and all that.

I was also looking to see if this was an option - right now all string configs kind of need a debounce timer added to them to prevent them from firing off with every letter the user types into the config. It would be very useful if there were two separate events similar to html's change event and input event so you would have the option of both/either live events and/or a single final event.