Passive 1: 15% Haste work with all Maokai spell.
Passive 2: The 6% damage increase debuff stack btw (up to 25 times). So, if enemy get hit by 25 of your CC, they receive up to 150% damage of all of our allies.
Saw Baus was doing some Ivern Jungle with TP and it inspired me.
So yeah, Ivern can clear jungle pretty fast (even enemy jungle)
You can probably get it down to 2:25 if you put up a ward in Krugs and have better pathing/Q than me.
If you don't like TP for the rest of the game, Spellbook is an option, but I kinda like it. It allows me to control the jungle, take up enemy camps the moment they show up and gank unpredictably.