Word of advice: as the time passes the number of review increases, as you know. But we tend to minimize the impact in the future. What you do today will come back in 1 week, than 2 weeks, 1 month and then 4 month.
In 6 month, the result will be today + 1 week + 2 week + 1 month. On top of that day.
If the charge is too large, it will takes weeks to decrease.
If you’re already at 400/day at level 8, beware of the burn out.
Thank you!
I made a mistake however, and looked at the review forecast instead of my actual number of reviews done per day (using the heatmap script). My mistake.
yesterday I had 219 reviews, the day before 166… and the maximum I’ve ever reached was 240 or so. It’s only gone past 200 a few times as well. So, the 400 number I got was actually ~400 per week. 
Would you say that’s a healthier number?
(note: this probably isn’t as relevant but I don’t go maximum speed, I go around 10-12 days per level.)
I find texting with native speakers is much more useful of an exercise than going through something like KS, if recalling words and kanji EN->JP is the goal.
Yeah, I started it a week ago or so, and cant bring myself to work on it because I don’t want to 1. burn out, 2. have another SRS, in all honestly.
Another worry is that I don’t want to train my brain to translate in my head before speaking or writing. But I don’t know if in the long run KS will promote this or not.
What you find manageable. 
I am on a 7d/level rhythm and I do about 300 reviews per day. It works, but when my job get hard it can be quite taxing.
I do find the current number reviews manageable for me
My schedule I created is made for 10 day level ups, but when I feel that my reviews are getting unmanageable with things I have going on outside of Japanese, I slow it down a few days.
Doing 7 day level ups is very admirable, especially being able to stay with your pace when things get tough. Keep it up, you’ve got this! 