Its alot easier to forget the kanji without the reinforcement of vocabulary. Not to mention that these are the same vocabulary we will need to understand and read Japanese anyways…
If its too much to handle, you can always go at a slower pace, especially if you grab the lifetime sale which runs until January 8th.
Otherwise you can essentially skip vocab lessons and reviews by using the Reorder script, which allows you to sort your reviews by radical, kanji, vocabulary, and also by level. You say that you’ve installed it already but it also works for lessons, so give that a try.