My suggestion is to definitely start giving more emphasis to grammar, and eventually to reading. With almost lv. 30 in Wanikani you definitely have more than enough kanji knowledge to get through most beginner grammar books. Also, there’s the law of diminshing returns: the further you get in WaniKani, the more rare the kanji you learn, and thus the less useful. Learning grammar on the other hand, will definitely expand your japanese abilities in a more noticeable way.
Since you have a limited amount of time, this will eventually come to balancing time between Wanikani and grammar. To do this in a smooth way, my suggestion is to start reducing the number of lessons you take in Wanikani; in a couple of weeks that will start reducing the number of daily reviews, leaving you more time to tackle grammar.
How many lessons you want to take will depend on how much free time you have, but a common rule of thumb is to aim for a specific number of apprentice items, since they are the ones that appear more often. You will have to do some trial and error here, but basically you aim for an specific number of apprentice items. For example, you decide never to take more lessons while the number of apprentice items is above 75 or 100. If you still feel you are getting too many reviews, you can further reduce the number.
It can also help to always take a specific number of lessons per day. Users going at full speed need to take 20-25 lessons per day, so you can aim for a more reasonable number like 10 or 15 (or even 5, if you don’t have much time). The advantage of always taking the same number of lessons, is that this makes your reviews more consistent and you won’t get weird spikes of big number of reviews that will affect your grammar studying routine.
If you are enjoying the SRS system in WK and you feel it is helpful, an option you can try is BunPro. This grammar site has a feature called “Paths” where it will teach you grammar points alongside your textbook of choice (A Genki path is included). It uses SRS to periodically help you review your grammar points and cement them in memory. However, it is not a free resource. They do give you a free trial for 30 days, though.
Another bonus is that it integrates with WK so the example sentences they show you will hide furigana for Kanji you already learned in WK, and it helps practice a bit of Kanji that way too. Just be careful not to take too many BunPro lessons at once too, or you might overwhelm yourself with two simultaneous SRSs.