You can kinda keep your reviews under a certain number just by having about 100-150 apprentice items max. Usually the others (Guru and above) won’t come all together, neither that often. Also, you might need to find a way to do your reviews more often if they are pilling up already at only level 6. The next levels will just be adding to your line of reviews and lessons. If you don’t have the time to do your reviews more than once every day, then I think you should slow down your lessons (10 per day, instead of all at once). But it would be really good if you could do your reviews at least twice or three times a day, with your phone during your way to work/school/etcetera or during a break, even if it is just like 15 minutes, or the higher levels might chew you out.
Also I don’t think such a request will be added to WK, but maybe someone has or could do a script for that.