Money aside, why can't the Glen Waverley line be extended to Rowville instead? It would open up an opportunity for better access to Jells Park, plus giving Wheelers Hill and Scoresby a decent alternative to the 754 and 757 buses which go all over the place taking forever to get to their destination.
Somewhere around Melway map 71 H3/H4/J5 would be a good place for an intermediate station, it couldn't be any worse in patronage than Laburnum or Tecoma or half of the other pointless stations on the Burnley group. The other stations would most likely be close to Scoresby Village (72 H7/H8?) and of course Stud Park. Provision for a future station in the 72 D5 region would also be a good start, before anyone decides to draw up even more spaghetti streets leading to nowhere. Having such a large gap between stations also means people would get from Rowville to Glen Waverley in next to no time, as unlike the outskirts of the Lilydale line, there are no lower speed areas such as the numerous 65 km/h curves (and one 40 km/h curve at Mooroolbark) between Lilydale and Croydon, and ideally the line would be double track.