It is usually so much easier working with offset than scale. Unfortunately, not everyone has the same screen size as you and the UI would therefore appear in a strange position or size. Therefore, it is best not to use offset for positioning at the final game.
What I usually do is to create the UI using offset values (mostly by adjusting and moving the UI around by dragging it). Once the whole screen is done, I convert the offset values to scale values. Then I work on the scripting aspect later so that it will not mess up the position and size of the UI.
You do not need to worry about manually changing the sizes and position of the UI element on the properties tab as you can adjust it with the dots:
I highly recommend using @ZacBytes’s AutoScale plugin when converting as it does this pretty well. I believe it is still working to this date. Here is the link to his topic: [Plugin] AutoScale Lite for GUIs - Scale your UI