The other thing @HaKatan misses which talks to your point is that you always need to look at how religious and toradik a sect is after they introduce a controversial idea. So especially did they stay as jews who are shomer torah and mitzvas?
Take for example Shabasi tzvi’s followers, what became of them? They became muslims. Now lets look at Reform jews? Nebach they intermarried and there is nothing of them. Now lets take conservative jews. The movement started as a means to keep people religous. The heter to drive to shul shabbos was because “out of a town” families were driving to the mall anyhow so at least draw them to shul and be mekrav them. Many of its rabbonim in the 1960’s were frum observant jews who never dreamed of chilul shaboss. In fact when Sol Liberman invited Rabbi Finkelstein to his vacation home in marthas vineyard, Finkelstein refused because it was the 9 days and he was worried that his children would go swimming if he went on vacation in the 9 days. Thats how frum they were. Yet what happened to the following generations? Did the conservative movement succeed in making jews more religous? Well lets look at where it is today.
Now lets look at other controversies, Where talmidim of R Yonason Ebishitz accepted now? I;d say yes. how about the whole controversy of chasdim that were put in cherem and viewed as borderline kefira at the time? How about R Hirsch’s idea of torah em derech ertez? All those ideals and more we look at its offspring and we see did it stick? Did it bring people closer to torah judiasm?
Now lets look at religious zionism. Are its people keeping shabbos, kashrus, learning torah and being shomer torah umtizvas today? Look around and see. i think its even stronger and they are more ehrlich then they once were. Can one possibly call them not jews or kofrim? I’d bet even the briska rav or satmar wouldn’t really think so despite all that they say on the surface.
HaKatan, has a very unique way of twsiting things into a pretzel. He has very narrow rules as to what counts and what doesn’t. Everything is a deep thing and if you can’t twist out of a his pretzel you must be wrong. Some things in our torah are not just what it says. Its what you see too. The obvious stares at us in the face. Of course you can’t just go with feel good judaism . if something is assur and clearly stated you can’t defy that. But there is no clear out issur that says One cannot be zionsits. He is inferring it with lgoic. This is where you need to draw a line and follow your rav.
P.S. our torah isn’t limited to Brisk and the Hungarian R Hillel Lichtnestien talmidim. (Nowdays its kind of one group). As R Hutner said about Briska rav, “The torah is nisht gegebn uf har grezim” and I’d add neither was it given on ” Har Yoel”.