I really enjoy learning vocab here and using the listening style reviews to train recall for when I’m writing, and then over writing more on my computer/writing self-study sentences/doing the reviews I can passively recall the kanji (I think active kanji recall is one of the things you can build up to after the N2 in Dec since that’s a tight timeline).
I also think doing this in addition to reading is a great way to get more vocab under your belt. The more words you can figure out through context through NHK or NHK easy, or in books or subtitles of anime the more locked in they are in your mind. I find that just looking them up isn’t as effective, unless you take the time to write it down in a practice sentence a couple of times.
Since you also mentioned struggling to recall words you definitely know from N5/4 just through listening, I’d suggest doing the listening reviews going through each lesson for each N level deck, and increasing your listening practice (whether that’s anime, podcasts, etc). Then, I think saying the sample sentence out loud will also help solidify that word in your mind too.
Hope this helps, and good luck!