I think it’s to stop people from shooting themselves in the foot.
If they allow users to view that information before making an attempt at answering the question, the user can convince themself that they know the kanji or vocab better than they actually know it.
WK is trying to help you to read Japanese, and when you’re reading, you don’t have the aid of your personal notes either. So WK wants you to fail the items that you can’t recognise as presented, so that those words can be lowered in the SRS and get extra repetitions. Rinse and repeat until you know the items well enough to recognise them in the wild without extra help.
So I don’t think any script can allow you to pull up any of that info without commiting to an answer first.
There are scripts with an undo function, which means you can technically input your guess, and undo it after checking the info, but you’d also see the general WK mnemonic, not just your notes. And that could quite easily set you up for failure and frustrations when you try to put all your hard WK word into practice later down the line.
If you’re worried about not remembering things well enough and making a lot of errors: that’s how it was for me, too. ^^ The first five or so levels, I felt like some words would NEVER stick. But some sort of switch flipped at some point, like my brain got more used to Japanese sounds and words, and things got a lot easier, even when learning very new and unknown words.
I’d personally advise to stick with the vanilla experience for a bunch of levels. If you don’t know a kanji or vocab when it comes up for review, you want to fail it, even though that red screen hurts. Then you can check the info, and try again, until you know what the item is without extra help. That’s the result WK is aiming for, so that’s why they don’t allow the showing of notes beforehand.
Best of luck finding your stride!