Apologies if I’m missing something obvious, but how do y’all revisit items that are already out of WaniKani’s rotation (if that’s even something that’s done)?
I guess I could setup something separate for this purpose, but I figured I’d ask first in case there’s a better way. 
Go to the item and unburn it
You can always use the self-study quiz if you’re ok with userscripts. WaniKani also has a feature for this, but it’s probably not the best idea to use if you want to reviews a few specific items (e.g. from a certain level) and have thousands of burns already.
Or, as already mentioned, you can also just unburn the items.
You can revive or “unburn” individual items, which is great for ones you have either forgotten or don’t feel confident with (I do this sometimes), snd you can also use the extra study review que which should be on the dashboard m. You nay have to scroll down a bit but it is there, and is great for a general review session of burned items.
Unburned items can be set back to Burn, if you no longer need them in SRS. There might be some limit to unburn-burn cycle, not sure.
Read them in native content
Thanks, all! Those are all reasonable suggestions, depending on the context. I guess I should have been more specific. 
What I want to do is just go through the whole list to be able to say, “Yep, I definitely know that with confidence,” or, if not, then unburn individual items to study again as needed (rather than unburning them all one by one preemptively to then decide if I needed to, or waiting until I organically encounter all of them at random “in the wild”).
I’m gonna give the quiz a shot to see if it fits my needs. Cheers!