in WaniKani, lessons are your accellerator. if you don’t want to go as fast, do fewer lessons per day. if you have a review overload because you’ve been going to fast, stop doing lessons while you get your reviews back down.
there is no need to go full speed, and the people who do go fast tend to have ample free time. but there’s plenty of people taking it slow, and that’s fine ^^
maybe check out these groups: https://community.wanikani.com/t/lets-durtle-the-scenic-route/ and https://community.wanikani.com/t/team-snails-on-vacation/ for others who are taking it slow ^^