Hi Karen,
At the moment, if you use logic with multiple response question type. It is not possible to show all hidden questions at once. Checking all options at once does not show all hidden questions. You can only check at one check box at a time, and needs to uncheck it before checking other checkbox.
The following is an example quiz.
Multiple Response Logic Test 2
If I am not wrong. What you require is for the hidden questions to remain visible when checking other check boxes. Which means checking 4 checkboxes at once will show 4 hidden questions. This is not possible at the moment.
Though, you can hire our developer for this custom requirement by filling a simple form at https://justhyre.com/get-a-quote/ if you need it on urgent basis. Otherwise, I can forward it as the feature request to the development team and they will try to implement it in 2-3 weeks.
Regards,
Kriti