Usually don’t suggest this since it goes against the WaniKani method of randomized reviews, but your use case clearly isn’t compatible with how their default system works. What you can do is use a userscript (or smartphone app feature) to order your reviews such that you get reading and meaning back-to-back, meaning that you finish item reviews for each item before moving on to the next item.
This is the one I use: [Userscript]: Reorder Ultimate 2 [newest] since I too sometimes forget my open review session and it messes up the unfinished reviews when I come back. It has a “1x1 mode” checkbox that does that for you.