As shown here : https://moodle.org/mod/forum/discuss.php?d=465563

Being able to use many "From" or "Until" in the activities restrictions (when NOT nested) leads to conflicting parameters and potential errors that are not automatically detected as such.

Example in attachment.

Improvement:
There should be a possibility to detect the use of more than one "From" and more than one "Until" inside one set of restrictions (maybe it makes sense when restritions are nested for specific use cases)  and flag it as a potential conflict.