Hi Tullio,

onfocus happens before onchange. When an element is already on focus, it will raise only onchange when the value is changed. We did not find any issue on our side.
In your post, you’re writing about sequence. The tab order for the focus depends on the tabindex property of the HTML Elements – any html elements, not just smart html elements. If you add the smart-check-box tag to your DOM, it will be in the DOM and after the DOM is loaded(use onload event to ensure it), then you will be able to use querySelector, getElementById, etc.

Best Regards,
Peter Stoev

Smart UI Team