I used the example setup for the ui-builder-element form to test it and wanted to create a form with multiple checkbox elements. Regardless if the checkbox is clicked or not the return value is always "on".
Hi there. Thanks for this. In fact, another user pipped you to the post in reporting this but don't let that put you off from reporting things. The more, the merrier.
The reason, it turns out, is that checkboxes fail is because they are the only input tag type that does NOT update the element's value property! What a bizarre and annoying find! But then, that's why uibuilder has the low-code capability in the first place - to remove all those HTML inconsistencies (and there are a LOT of them as I've discovered the hard way!).
Good news is that the next release not only has the fix but also some enhancements.