Duration.

So unless I missed something, nothing in NA says what affects the duration.

When I get the speed boost (got it 3 times in a row, the game must realize I'm human and want to pity me) it tell me it'll last for "11minutes", at total level 17500 and potential level 67.

It seems like each kind of boost might have its own duration.

At Rank 5 Palalan Embrace, I received a Combat EXP x2 boost, that lasted for 30 minutes. Now at Rank 4, I received a random stat boost that lasted 26 minutes.

About the random stat boost, I feel like the boost comes in 3 separate parts.

Part 1 will choose either HP, MP, or SP to boost. Part 2 will choose either Str, Int, Dex, Will, or Luck to boost. Part 3 will choose either Crit, Defense, Protection, Max Damage, or Magic Attack to boost.

Or at least that's what I've observed so far.

Okay, the duration must be different for different things. Rank 1 Palalan Embrace got me an Exploration EXP boost, that lasted for 35 minutes.

I'm really thinking the duration is either semi-random or different for different effects. I just received a 2x Combat Experience boost that lasted for 45 minutes, rather than 35 minutes for some other boosts I've gotten at r1.

Probably different for different effects now that I've seen it a bit too.

The Combat EXP buff has a different duration to all other buffs.

All the other buffs have the same duration as each other.

I've prepared a new summary proposal which should communicate that more distinctly. It's on my UserWiki page. (I can't figure out how to create a link to it..)