These things are not part of the API and so there isn’t a way for a script to access them in bulk like that, sorry.
It’s just the way that works for me! 
My progress is strongly tied to my motivation, and my motivation will drop significantly if I’m rushing through my reviews and getting too many items wrong, especially ones that are at the tip of my tongue.
Perhaps you are able to bypass that motivation drop, or you have a better memory than I.
If you say “too many wrong” what ratio are we taking about?
Im fine with 80-90% correct answers in reviews.
At the beginning of a new level it might go down to 70% for a session or two.
10 seconds per answer is a long time across 100 answers…
If i look at an item and cant immediately fill it in i do not consider that knowing.
To each their own, I guess. Usually I’m between around 87-93%.
You only know an item once it’s burned (or should do anyway). Up until that point, you’re learning it. I prefer to try to recall the vocab/kanji rather than just hazard a guess, or skip it after a second’s thought. Just my way - maybe the reviews are longer, but it keeps me motivated, and keeps me going. Works for me. 
edit:
Out of sheer curiosity, I just tried doing my reviews as per your method - I can see how it could work for some, but for me it’s not fun, just stressful!
I like the battle of trying to recall things I have recently tried to learn. Just dismissing them and moving on is like throwing away your keys because it took too long to find the one to your car (to me)! Learning has to be fun, and it has to be motivating, and everyone is different! Your way works for you, and that’s good. My way works for me!
Anybody could find the list of kanji and make their own decks. What Wanikani is selling you is the ordering, the convenience, the mnemonics and the context sentences. They’ll never give that up in the API as they would no longer have a product to sell.
edit: forget what I wrote above
Don’t they sell context sentence workbooks? Could you just use that?
Whoops, forgot they closed the whole store, not just the physical store.
This is not quite correct. Mnemonics and context sentences are exposed in the API. The Item Inspector script can export this.
aah, I stand corrected, haven’t looked at the API doc in a while.
For all intents and purposes, the api is theoretically not free. At least there’s a usage guideline, that you shouldn’t let free users have access to content past level 3. Also, those context sentences and the mnemonics are copyrighted.
Does anyone know of an extension that has an accurate percentage gauge while reviewing?
A way to have vacation mode auto-activate after being inactive for a set amount of time, e.g. you can set it so that if you don’t do any lessons or reviews for three days then vacation mode will automatically activate. Idk if something like this is even possible though…
You can see if a user is on vacation, but it doesn’t look like you can change vacation status in the API.
That’s what I feared 
Oh well, I’ll keep hoping.
I’m sure you could figure out the unofficial API, though
I mean you could figure out which calls the native code makes to enable and disable vacation mode, and just replicate those, rather than using the official API
Honestly… and I’m sure this has been discussed, but I would like a WaniKani app? I have checked the Google Play store so many times over the years. I no longer have the dedicated time in front of a computer to study kanji, and I really enjoy doing it on my phone! The third-party apps are dying. Why is there no official app?
Hakubun is seeing active development (but of course, like most projects, being done by a single person means this is a slow process that takes a back seat to other irl matters); seems like it has just been submitted to Apple for beta so soon iOS users can try it out too. And Smouldering Durtles is the continuation of Flaming Durtles and is actively maintained.
But should you not want to go third party, you can also just use Wanikani as a Progressive Web App (PWA) wherein you ‘install’ it to your phone/tablet like a separate app, but it is more like a specialized shortcut to a mobile focused version of the website. (Installation is usually done through your mobile browser; navigate to the website and check the browser’s menu for an ‘Install’ option). This would only support a vanilla experience on iOS however, as Apple does not allow browser extensions for browsers on their platform (else Firefox would certainly have done it by now considering they already have the framework with Firefox for Android); this isn’t really a drawback to your desire however, as an official Wanikani app would never give anything other than the vanilla experience either.
Does a script exist (or is this somewhere in the vanilla settings) to customise the Wrap Up feature? I would like my Wrap Up feature to only give me the half-completed cards if there are any remaining. For example if I’ve already answered the reading, it prioritizes the meaning card. It doesn’t add any new cards but rather just helps me finish more quickly if I need to step away from my reviews.
A script that celebrates when you answer a leech correctly would be nice.
Seconded. This is my favorite thing about Smouldering Durtles. When I hit wrap up it’s because I need to go asap. In the meantime you could try the back to back script, at least that way you would never have half answered items left in your queue.
I’ve beefed up my already previously beefy (and formerly no longer functioning) userscript with this functionality.
I would say the feature is “post beta” at this point, but I’m not certain there are no bugs at all for now.
If that doesn’t turn you off, check it out here.
You’ll see two new icons during the reviews session.
I haven’t written up a detailed description of how they work, but the basic behavior is:
- Left button (Filter Wrap Up to Only Started Items)
- Enable the started items filter for the wrap up button.
- Disables the right button (to emphasize that it has no effect when this is toggled on).
- When the wrap up button is toggled on, filters the queue to any items that have been partially answered and the current item.
- When the wrap up button is toggled off, retrieves the standard queue.
- If no items are partially answered, simply sets the current item as the only item left in the wrap up queue.
- Right button (Wrap Up Item Count)
- Sets the queue size that will be used when the wrap up button is pressed (i.e., instead of the default 10 items).
- Automatically caps the number to the maximum reviews available (i.e., prevents you from inputting anything higher)
- Similarly works with toggling on and off as the filter button.
Edit: It does seem like it still causes some weird behavior when stopping a Wrap Up session after having already filtered it. I don’t plan on fixing it today but will look into it more when I get some time.