(Warning long incoming spergy comment.)

which means that citizenship can only be acquired through hereditary means.

That's essentially what I'm describing above. It's a more flexible way to do it. Ethnostates in the modern world need to deal with the fact that it's easy for people of even modest means to travel everywhere and race mixing has already occurred in many regions.

You need to have a way to legally reward the edge case people that all societies have and genetically bring them back in to the extended family. With the rigid hereditary system you describe you're going to have a lot of hybrid whites and white presenting people that contribute to the state, may love the state, but can never have a path to full citizenship over generations of service.* When you have no path for these people they fall easily into Jewish ideologies and become enemies hidden within. I don't want a system that's so rigid it's easy to attack by liberal minded types. I think this is big reason for the Russian civil war. For generations the aristocrats and orthodox church was struggling to govern too many different ethnic groups and it had a shrinking group of 'core' Russians. Jews seized on the opportunity to convince these edge case groups to form together as an ideology against the state and church. Many core Russians that attempted to maintain alliances with the church or had generational land, i.e. the Kulaks, were wiped out in the chaos. Someone that knows Russian history please chime in if I'm wrong.

Another problem, when you have a hereditary only system the state runs the risk of creating a smaller and smaller gentry. The gentry then forms into closed off aristocrats. The other issue with hereditary only is that it creates a purity spiral. You can't have factions constantly arguing about who the purest whites are. Hitler saw this problem as well. Slavic peoples were a problem because they were allowing the ideology of communism to spread through Europe. Hitler bashed slavs as he rose to power. I don't think Hitler hated slavic people but hated the divisivness the slavic state: Russia was bringing to Europe. As he gained physical control of Germany and heavy influence over continental Europe he realized there were lots of areas with slavs, and Germans in close proximity that would need to be governed peacefully. He realized there were lots of non Germans that were still Germanic in blood to some degree. That's the idea behind the 'people's community'. Share my blood and you are my brother. Share my blood but seek to undermine my ethnostate? You're out. Part Jews (aka mischiling Jews) were also allowed in the people's community. Even Hitler believed there were some good Jews.

*you might be thinking to yourself this 'dilutes' the white race. I disagree. In fact it can be used as a way to dilute and 'bleach' Jews into becoming more compassionate and high trust i.e. white. I'm not proposing genocide of the Jews of course. I want them to live safely and peacefully in their own lands away from whites. Before this law would be passed I'd give Jews time and shekels to leave. If they stayed or obscured their identities to stay in a white ethnostate then their children would slowly be more white over time naturally. That's their parents fault not the states fault. It's also really important to point out that this whole people's community doesn't work if you import millions of non whites for labor and they want to be on the path to full citizenship.