I’m someone who follows this exact method, with a 3 vocab to 1 kanji ratio, equating to roughly 9 vocab and 3 kanji lessons a day, and I absolutely recommend it. I didn’t start out doing this, though, so I’m not exactly sure how to advise for the initial levels .
For the first level, you’ll probably be fine just doing the lessons as they’re unlocked, since you don’t have much content circulating yet. If you’re not sure about ratios, you could just pick a daily number of lessons and limit yourself to doing that number and just do them in the order that WK gives them to you for now.
It looks like from about level 4 onward, there’s a more normal number of vocab lessons (the earliest levels have fewer), so the 1:3 ratio will probably be easier to do.
What I did when experimenting with lesson ratios was keep an eye on the number of items per level on wkstats. If it looked like I was going through vocab lessons faster than I was unlocking new ones, I’d do 4 kanji a day (and one less vocab lesson) for a few days instead of 3. The main thing is keeping the number of daily lessons the same in order to cultivate a consistent daily workload.
For the radicals, the earlier levels have way more of them than the later ones. At the beginning, I would often do all of the radicals in one day because they took way less mental effort to learn, and it was simpler just to get them out of the way. If this is too much, you could always split them into multiple days, though!
But yeah, for the very first few levels, I don’t think it hurts too much to binge the lessons, since you don’t have older reviews coming back on top of that, but it might still be a good idea to try doing a consistent daily amount, especially if you’re new to Japanese and are trying to adjust to a completely different way of thinking about things. The early levels have a lot of easy kanji/vocab, but also have a lot of kanji with loads of readings, and vocab where all of the readings are exceptions (like the things and days counters), so if you start to feel a little overwhelmed by failing a bunch of them over and over (as was my experience… ), it’s okay to leave lessons undone until you feel like you’ve actually started to wrap your brain around the stuff you already have in circulation.
Basically, don’t worry too much about your pace for the first few levels, but if you do want to establish some early habits, you’d be fine just picking a daily number of lessons (like 12 or 16) and using WK’s default order for now.