Back to the main conversation!
I would say that I did something similar (you can read it on my lv 60 post), which I would not advice from a learning perspective, but it does its job as managing the work load: I did all my levelup lesson on the same day as level up for lv 60 - even though 1 was lagging behind on quite some of the lv 59 vocab lessons - I blame @saibaneko my couch and comfy zone, but yeah, yeah, for learning, it might not be ideal.
As for work load, it pretty immediately kills off the workload in the minimum amount of time, as when you have no more lessons = reviews immediately go down. (within a week, not months)
That spike is aggressive and meant doing daily 290-400+ reviews plus at the top end, but usually between 250-350-ish and demanding some constant mental space.
It died out in weeks after and then slowed gradually down to a real trickle.