If I change a picture or color, centering, paragraph margins, etc ... I need to do so for all breakpoints unless I want to keep them different.

The actual text content doesn't behave the same way, however ? If I change text for one, all get the same changes automatically. Yet I want the mobile text to be a series of concise bullets and the long drawn out full sentence paragraph for full screens. How would I accomplish this ?

In the Design panel one can choose for a paragraph or other element 'Display None' instead of the other Display options.

The above means that one can create a switching of paragraphs or other elements as in the following example which has both a long paragraph (LP) and short paragraph (SP) in the same row, column, or other container.
(a) For mobile width(s) LP is set to 'Display None' and SP is set to 'Display Block'.
(b) For full screen width(s) SP is set to 'Display None' and LP is set to 'Display Block'.

Frank

Thank you