Either while pressing ctrl or in general. It would make it easier to read long cards during a duel. Also possibly allow an option to scroll line by line through cards, rather than in blocks of text.
Global scrolling is not possible. Play any simulator - Dueling Book, ygopro, etc. You will never have the ability to scroll with your mouse wheel and also turn the pages of the text. But there’s already a solution to your question. The issue with all sims is that you have to move your mouse over the card to scroll. While moving the mouse, you may hover over a new card that’s on the field and now you can’t read the card you were currently reading. That’s the issue with all sims.
This however is fixed in omega. Just hold CTRL while moving the mouse and this locks the display card pic.
I’ve been playing ygopro for 7 years though and now I don’t even read from the text box or the display pic. I simply click and hold on the card and zoom. Then read it as if I were playing the game irl.