There are a few things which I think I should clarify.
First off, that VIF link is very interesting, and I have a lot of reading to do. For what it's worth, extending the 2026 figures through to 2050 generally gives totals of around 870,000 residents in the Greater Ringwood area, of which a little more than half will be of working age (18-65). But there are two problems with that: it doesn't allow for an expansion of the definition of 'working age', which is long overdue now that people are living longer. What if the normal retirement age was redefined to 70 years old, or 75? Also, at 870k residents, that works out to around 1,700 per square kilometre. Apparently, Tokyo is at around 6,000 people per square kilometre. I'd like to think that in the very long term, 3000/sqkm is a reasonable goal?
Secondly, all my urban planning work is focussed on 2050, and how to get from where we are today, to how I think we should be in 2050. That's very different to what would happen if everything were left to its own devices.
Third, from a timetabling perspective, anything above thirteen trains per hour (stopping all stations) from Box Hill to Ringwood will block the ideal 3tph express.
Those thirteen commuter trains between Box Hill and Ringwood won't be able to carry more than 26,000 people towards Ringwood.
Yes, I'm still focussed on Ringwood as a central location, because it fits nicely with the 60min rule. Having peple west of Box Hill commuting towards the GPO, and people east of Box Hill commuting towards Ringwood, is the bestway to cut down travel times in the eastern corridor.
As AZN said the VIF forecasts for these area are assuming growth through densification. There isn't any unused greenfield land in these areas for subdivision. The 55,000 extra population is through ~20,000 extra homes either in units, battleaxe subdivisions or brownfield redevelopments (eg. Boral Bricks corner Stud and High Street Knox).
The area I've got marked for 'Greater Ringwood' is around 430-470 square kilometres. It stretches from Box Hill to Mount Waverley, Scoresby, Knox, Belgrave, Lilydale, Warrandyte, Templestowe, Doncaster and back to Box Hill.
In that area a lot of the housing is still only one or two stories tall. There is a lot of capacity for vertical growth, not to mention the currently unused land west of Lilydale, and along Dandenong Creek. (No, I'm not worried about flooding - build the apartment blocks on stilts.)
And using my 30min by rail guideline, looking at door-to-door commute time as the only method of measuring you could justfiy including Yarra Glen as part of Ringwood's commuter base. That would bring the land within a 60min door-to-door commute of Ringwood central to around 500 square kilometres.
And it will AT BEST be third in line for any state government redeployment (Dandenong, Footscray (and I'd prefer Box Hill ahead of it too)) and it isn't geographically competitive in a greater Melborune sense for a private sector industry to relocate.
That's the good thing about planning for 2050. I accept that Dandenong and Footscray (and Geelong, Ballarat and Bendigo) will be higher priorities, but once they're started then attention can be moved towards Frankston, Ringwood and Broadmeadows. Then a series of smaller cities can be included; possible examples might include Epping, Greensborough, Hastings, Werribee, Melton and Sunbury. These would only be included in the MBDs for one of two reasons: either travel times are over 60min, or there isn't enough room in the key cities to supply enough high-pay jobs. The latter is far less likely.
Aside from the main cities, there will also be a range of areas with a non-corporate-business, more commercial focus. I'm calling these MCDs. Examples (working clockwise from north) can include Reservoir-Bell, Wollert-Aurora, Mill Park, South Morang, Mernda, Heidelberg, Box Hill-Doncaster, Lilydale, Glen Waverley, Chadstone, Upper Ferntree Gully, Monash Clayton, Narre Warren, Berwick, Pakenham, Cranbourne, Carrum Downs, Southland, Edithvale, Langwarrin, Baxter, Mount Eliza, Mornington, Somerville, St Kilda, Newport, Laverton, Point Cook, Werribee South, Sunshine, Milleara, Deer Park, Sydenham, Tullamarine, Moonee Ponds, Craigieburn and/or Coburg.
Most MCDs fall on or near a border between MBDs, and would not be restricted to those boundaries. However, jobs within an MBD boundary, whether or not they are generated by the MCD, would be included in the job total for the MBD. So the total for the Ringwood MBD jobs includes those in the central area, plus those in Lilydale and Upper Gully, and about half of those in Box Hill and Templestowe and so on, along with all the small shopping strips and other jobs in that huge area.