Y'all are overthinking things. Most of the Pacific annexations were totally useless so far as the colonizing power was concerned. With notable exceptions - especially Hawai'i and New Zealand, they were nothing more than expensive prestige projects flowing out of a very specific socio-political situation in Europe (and Japan's response to it). Change the situation in the Pacific as much as you like, the power differentials remain, and will take you to roughly the same place.
You have to rearrange Europe to get much further than preserving, say, the Hawai'ian monarchy under a British or American protectorate.
There are several options I see:
Eliminate the Raj. British India was huge, profitable, and outrageously prestigious - it and America were models for just about every colonial project of late colonialism. Without it, the late nineteenth century and early twentieth would probably lack anything like the Scramble for Africa. Colonialism would remain more based on need, profit, and settlement - taking most of the value out of most of the Pacific. The big late colonial rush would be more like the Scramble for Spheres in China.
Earlier European Decline. If the first of 2-3 European total wars starts in the late nineteenth century, there may not be energy to reach the peak of OTL colonialism. A lot of places in the African interior and Pacific might then slip through the cracks.
Free Aotearoa. If New Zealand isn't colonized, or at least isn't settler-colonized, that might reduce attempts to repeat the feat north and east of it.
Earlier Nationalism. If Germany and Italy unite a half century earlier, their urge to find a place in the sun may pass before Pacific colonization becomes practical.
Greater British Dominance. If Britain strips all other Europeans of their colonies - because the revolutionary French are never dislodged from Europe, for example - then there's no longer any competition. No one annexes anything to try to be like Britain, and Britain doesn't annex anything to keep it out of anyone else's hands. In that case you could easily see most of the Pacific with political continuity as nominal vassals of the Crown.