Ultimately, the answer to your question depends upon if you plan to do reviews every day or not. If you do not plan to do reviews every day, note that there is no way to adjust WaniKani’s SRS stage timings to fall on the occasional/sporadic days that you plan to do reviews. The SRS stage timings are only dependent upon previous review accuracy, the previous SRS stage, and whether or not you pass or fail a review. Also, the SRS is meant to remind you about an item (radical, kanji, vocabulary) just before you forget it, so lengthening the review time can decrease review accuracy (depending upon the person). For example, if you learn a new item on Day 1 and don’t do reviews on Days 2-4, then you’ll probably forget it by Day 5. You have a much better chance of remembering it 4 hours later on Day 1 (Apprentice 1 → 4 hours → Apprentice 2), 5+ hours later on Day 1, or on Day 2. Therefore, reviewing every day is advantageous.
If you do all reviews every day (keeping up with previously learned items), then you may be able to do 2-3 days worth of new lessons at once. I think that the default number of lessons per day is 15, so you could do 30-45 lessons in one day depending upon the number of available lessons (see WaniKani Lesson Settings dropdown below). However, keep in mind that adding new lessons increases your daily review count which can easily become unmanageable and cause burnout. To keep reviews manageable, I’ve seen many in the WaniKani community use an Apprentice count cutoff below a certain number, with the upper limit/cutoff ranging between 50 and 150. For example, when the Apprentice count is below 100, it is okay to add new lessons, but when the Apprentice account rises above 100, no new lessons are added to prevent burnout.
WaniKani Lesson Settings
You can use the lesson settings to increase the number of lessons per day (without using the advanced button): https://www.wanikani.com/settings/app
Or, use the Advanced Button/Lesson Picker to select the maximum number of available lessons: Lesson Picker | WaniKani Knowledge
Yes, these small pockets of time can be used for WaniKani. There are multiple ways to take on small review batches:
Wrap Up Button (Vanilla WaniKani)
- In vanilla WaniKani (no scripts), hit the wrap up button when you start to take on only 10 reviews. Or, hit the wrap up button anytime during the review session to take on a maximum of 10 additional reviews.
- Before hovering over the wrap up button, it looks like:
- While hovering over the wrap up button, it looks like:
Batch Size (3rd Party Apps)
- Some of the WaniKani apps (3rd party) give you more review flexibility. For example, in the Hakubun beta (iOS and Andriod) you can change the batch size to less than 10:
- 3rd party app options include: Smouldering Durtles, Tsurukame, Hakubun, etc.
WaniKani User Scripts (3rd Party):
-
Reorder Omega: I think you can use reorder omega to do a batch size cutoff for reviews: [Userscript] Reorder Omega
Try something like this (creating a new preset for each review batch size you want):
-
I’m not sure if there are any other user scripts that manage small review batches, but here is a list of 3rd party userscripts, apps, etc.: The New And Improved List Of API and Third Party Apps
Edit: formatting, additional wording to better address question