At odd times you will be faced with some of the confinements of the new UI. One example is using an Option Set at the bottom of a section. After publishing you find that the actual drop-down is only showing two lines at a time. This is an undesired effect of the new UI. You are confined to a container, and the dropdowns do not know to extend past the borders of the container they live in. Here is the design:
And here is what you end up with on the published form:
Indeed, not very user friendly, especially when your selection list is longer.
Of course, you could try to relocate the control somewhere up in the container, but what if that field makes logical sense to be at the bottom of that container?
The solution is quite simple, the friendly Spacer comes to the rescue. Take a Spacer and add it to the bottom of the container. Now your form designer will look like so:
And now the users can breathe easy, as they can see a proper drop-down with more lines:
Add as many spacers as needed until you get it looking the way you want. Be mindful of the blank space you create underneath though, don’t exaggerate.