Like @seanblue says, the easiest way to speed up is to prioritise radicals and kanji when you level up. ^^
My pattern was: 18-24 lessons a day. With reorder, I would do a level’s kanji first (doesn’t all have to be in one go) and in the days it takes to get first and second wave of kanji to Guru, all my vocab would be taken care of.
I did keep this up while being able to review more than twice a day. If that is what you have time for, it will probably also slow your level-ups a teensy bit.
For example, for those that can review at least three times a day, they can do lessons in the morning, review them four hours later, and review again in the evening eight hours after that. That means a word hits Apprentice III on day 1, rather than the Apprentice II you can get it to with 2 review sessions. Those people will clear items out of their Apprentice pile more quickly, so if they’re sticking to max 100, they’d be moving a bit more quickly. Not saying you have to magically find the time for more reviewing, just that it does impact speed.
Hitting those early intervals often also helps retention, so some items may not be moving out of Apprentice as quickly as some errors may be made. But you would know that better than me. If your retention is fine: great! 
I’d say experiment if you feel a need to speed up. To possibly avoid leaving yourself with too many reviews during those two times a day, maybe something like @Kumirei 's Expected Daily Review Script can help.
Good luck! 