Australia

More density is great, but you're taking it to some rather ridiculous extremes. 1 km is a really large radius.

Looking at Wooloowin Station in Brisbane, 1 km takes you to the opposite side of Lutwyche Rd in the west and Sandgate Rd in the east, which are areas that are very obviously not connected in terms of locality to Wooloowin Station.

The guideline for good accessibility is usually a 400 m walk to public transportation, and I think that means it's also a good guideline for where the increased density should be located around stations. (It's a bit borderline on account of the walking distance being the indirect route taken on the ground, while the radius is a simple "as the crow flies" distance, but it's a decent guideline anyway.)

50 m tall is, according to this report from the city of Victoria in Canada, 17 storeys. That would make 100 34 storeys and 150 m+ a minimum of 51 storeys. That's huge.

But we can achieve much greater density on the whole without going to such extremes. So-called "gentle density".

Council’s current approach has been “avoid changing anything at all, but when we do change, push for the tallest towers we possibly can get away with”. My policy would be almost the opposite of that. I would make widespread sweeping changes across the entire city, but the scale of those changes would be fairly small. I'm using Brisbane City Council terminology because that's what I'm familiar with, but similar concepts should apply:

I would eliminate all LDR and CR1 zones entirely and replace them with LMR3 and CR2, respectively. LDR allows only single-family separated homes. LMR2 allows 2–3 storey apartments and townhouses, as well as granny flats and duplexes, while not outlawing single-family separated homes. Then, I would make everywhere within a 400 m radius of a train station HDR1 (with the caveat that my version of HDR1 would still permit townhouses and duplexes like the current LDMR and MDR do, but which current HDR does not, while still not permitting single-family separated homes). Between 400 and 1000 m of a train station would be MDR. MDR is 5 storeys, HDR1 is 8 storeys. HDR2 (15 storeys) could be used for major important train stations, but really I don't know if I want to see anything more than 8 storeys further out from the CBD than about 5 km.

But that first step is really the most important. You could get a doubling or more of available density just by removing all the low density and replacing it with a gentle sort of medium density, with the higher density areas sort of like the spice on top.