I started the habit of doing at least 3 or at most 4 sessions a day:I feel you. The problem with WK is that if you slow down a single day, things pile up, so you have to create a whole system around it and schedule it so that you can do other things on top of it.
Its very time consuming, but its also very effective. I will try to balance it a bit more, trying for 12 days in average, to see how it feels. This takes 95% of my available "japanese studing time", so its a good thing we are also learning vocabulary on top of the Kanji.
A morning session, where I do reviews and about 10 to 20 new lessons,
a lunch session where I'll rereview the morning lessons,
sometimes an afternoon session where I can re-review the failed items from my lunch session.
And lastly a session before going to bed, where I'll do the last review of the morning lessons for the day.
So this fits perfectly with the WK SRS interval: 4 hours, 8 hours and 12 hours for the failed items.
My sessions don't take up more than 15 minutes expet the morning one.