Move “important notes” field to replace “additional information” field

WP: 5.1.1
WC: 3.6.2
WC Checkout Manager: 4.3

We have hidden the “Additional notes” field on our checkout page.
Now, in order to eliminate white space and make our checkout page fully visible without scrolling, we would like to move the field “Important Notes” (checkout notices, which is now placed before the order summary) to occupy the empty space that has been created by hiding “Additional notes”. However, we can’t do this layout change.
Here is a screenshot

Can anyone pls suggest a solution? TIA.

Csaba

The page I need help with: [log in to see the link]