The Reorder Omega userscript allows you to perform self-study reviews, which you can filter by WK level or by SRS level, among other things.
You can also similarly filter your actual reviews, though I wouldn’t recommend that, as it could undermine the benefits of SRS.
Another option for level-specific review is utilizing the context sentences. Their original intent seems to be to allow you to see how a vocab word is used in context, but they’re also super useful for vocab practice if you can arrange to have them randomly served up to you. I’d love to see a user script for this.
My solution has been to copy and paste them all into a Google Sheet workbook (with a separate sheet for each level), with the English translations invisible (white text on white background) until I click on them. That way I can randomize the order of all the sentences from a given level, and practice that level’s vocab by reading the words in context, as has been so heavily promoted in this thread. Alternatively, it’s not hard to write a script to pull a random sentence from a random sheet (i.e., a random level), for more comprehensive review.
For levels 1-30, most vocab words come with about 3 context sentences each. Level 9, for example, has 453 context sentences. That’s a bunch of reading practice per level, while also letting you specifically focus on level 9 vocab, and also incorporating random occurrence of words from prior levels as they are used in a given sentence. Plus, those sentences are all customized to include only (mostly) kanji you’ve learned, which makes them arguably the most personally customized kanji reading practice you’ll find anywhere.
I try to stick to a WK pace of 2 levels per month, which means I’d need to read 20-30 sentences every day to get through them all. I’m currently reading through the sentences about 8-10 levels (4-5 months) behind my current level, to refresh those words that might be starting to fade from memory, and at this point, I don’t feel much need to look for extra reading practice or extra vocab review.