In Customizer > General > Site Layout there’s the option called “Elementor Section Gaps” which allows choosing between “Theme Override” and “Elementor Default”.
This option mainly refers to the Section element’s gaps between Columns.
Elementor Default
This means each Column inside a Section will have a 10px all-around padding (depending on Gap size).
Basically this is just inner padding, not actual gaps, because both first and last column will have a side padding. Also the margins will make the columns unequal. It’s very difficult to have control systematically over them.
Here’s a video recording showing this behaviour https://d.pr/v/bHupJJ .
Theme Override
Unlike the Elementor Default behaviour, Rey’s overrides force Columns to be divided by equal gaps, regardless of the padding of the Columns.
Please follow this quick recording showing how the gaps are behaving https://d.pr/v/bVUXZq .
This offers the best of both world, by allowing better and easier control over Gaps, while still allowing full padding adjustments with “No Gap” selected eg: https://d.pr/v/c0CnQC .