Idealism = We have a lot of people believing X ideology therefore we can now implement X political regime
Materialism = We have X political regime which will cause people to believe Y thing (think strauss-howe generational theory), the ideas and rules in place will determine how everyone else behaves and we can't just put any political regime we want into practice, we can only accelerate or decelerate the process of moving to the next regime
NiSe valuing = central quadras: beta and gamma
SiNe valuing = peripheral quadras: alpha and delta
It kinda makes sense 'cause Ne valuing types see ideas in an extraverted way in the sense that "I have an idea and I have to convince as many people that it is a good idea without using force" which is kinda the premise for idealism "a lot of people believe this so we can implement a new economic system"
Ni valuing types also see the development the world as somewhat inevitable (fate/destiny) which is the premise for materialism
You can also compare alphas and betas and see that they're essentially an idealist and a materialist version of the same thing. Both are Ti valuing so they whole-hardheadedly admit what they believe and don't hide their own personal agenda. However in any situation where you have to spread an ideology alphas see the world as they having an idea that they have to convince as many people of (Ne) bringing arguments, debating etc. while betas see the world as an idea they have to fight for (Se) and generally see every individual as needing to fight for their place in the world. This is very similar to alphas who also believe that everyone should (at least be willing to) fight for what they believe in, only that in an idealistic way: we have to convince as many people that our idea is right and after everyone believes in it we can put it into practice. Compared to betas to believe that everyone should (at least be willing to) fight for their place in the world: so they instead believe that convincing people is useless and instead we need to make concrete changes in the world (kinetic force, Se) to advance our ideology: this is materialism.
You can see deltas also share the alpha Ne thing of trying to put an idea in as many people's heads as possible, only that they won't fully admit their own agenda (Fi valuing), you can see an example below (Example 2 for postmodernists).
Typing ideologies this makes a lot of sense since classical marxism (think the one practiced on r/stupidpol ) is beta (fighting for ideal reality etc. all that beta shit) and is also materialist while "radlibs/SJWs/cultural neomarxists/postmodernists/etc." are delta/NFP and also idealistic so it again makes sense (example 1 and 2 ), also both anarcho-communism and right libertarianism (the NAP) are pretty alpha ideas and also idealistic so it all checks out for alphas, betas and deltas (i've yet to find a materialist gamma ideology though)
Keep in mind that being from a certain quadra doesn't mean you'll adhere to its ideology (typology has little to no effect in what you believe politically) but it rather means what ideology you find the most "natural", maybe even the "default". For example as an alpha (ENTP) I always saw right-wing libertarianism or even minarchism as the "default" ideology. It needed no explaining as to why it's a good ideology, it came natural to me because it is the "Default". However I don't adhere to that ideology anymore since I have arguments to support why it is bad and why other ideologies like social democracy are better. But because I'm an alpha I needed arguments to support why minarchism is bad in the first place, someone from another quadra would find it more obvious. Ideas like democracy, freedom of speech, "you are free to do whatever you want as long as you don't hurt anybody else/you don't infringe on other people's freedoms" (the NAP), etc. all come natural to me as an alpha. So that's why I view the world as minarchism/classical liberalism being the "default" and then if you want to prove to me that another idea is better you better give an argument as to how it improves people's lives.
That also means that central types can be idealistic and peripheral types can be materialistic, just not by default. You don't need to convince a peripheral type to idealistic but you'd need to convince them to be materialistic. When I first heard of materialism I was like "huh, interesting..." while a beta/gamma would probably find it obvious in the first place.
Strauss-howe generational theory is an NTP way of looking at NiSe materialism. It has the Ni premise that the attitudes and personalities of some people are inevitable and are just a product of our environment as well as the fact that certain events in the future will be inevitable (some sort of fate) and brings an NTP-ish model to justify it. This is why the theory is a very NTP thing since for betas and gammas you wouldn't need to prove to them that certain events and personality traits are a product of past events, it is obvious for them, instead with them you'd jump straight into describing what they are (while with alphas and deltas you'd need to explain both).
there doesn't seem to be anything here