Everytime you post here you're really long winded and not clear with what you're asking. What are you trying to say??

we'll use the Jewish colonization of Palestine which most White nationalists oppose

Most Europeans oppose it not just 'white nationalists'. Genocide is a shitty word charged up by holocaust propaganda. Genocide seems to only be thrown around when talking about white history to shame whites for surviving and thriving.

How do you reconcile opposing that (or generalplan Ost if you do) while being okay with ethnic replacement of Native Americans?

90% of natives living in North America were dead in a generation of exposure to European explorers. That's not the Europeans fault. Nobody at the time understand contagious disease very well. Pre and post small pox epidemic 90% of natives were at war with each other and engaged in genocide towards each other. A waring and quickly depopulating area is going to be conquered by whites or by someone else. And let's be honest, who really made a lot of the decisions to keep putting natives and small and smaller reservations? Who made the decision to go to war with them on the Prairie? Not 'whites' not 'Europeans' but a small group of government officials tied to elite families that for the most part hate everyone but themselves. Not every European was a blind expansionist or pro conquering and colonizing. The Germans had almost no colonies and constantly discouraged it.

Natives were absolutely genocided but not in the same way the Palestinians are being genocided. Whites are currently being genocided by the Jewish merchant class and their traitor allies. That's my concern right now. Not some historical argument. Not some weird moralizing argument. Jews don't give a shit about morality. The seem to only care about accumulation and get everyone around them to fight and die against each other so they can profit.