There are other priorities on our network, but with providing a service to connect with the Yarra Valley is something I’d like to seeThere is already an hourly service (give or take) to Yarra Glen. It's called a bus, and it costs little to run in terms of infrastructure. While the YVTR might get away with existing at-grade level crossings, such as those at Yarra Glen and Healesville, it's doubtful if any kind of Metro service could do so, thus requiring grade separations at Lilydale, Coldstream and Yering. Add to that the problem of the flood plain with its numerous bridges, not to mention the complexities of new track and signalling, and the bus service looks even more attractive.
Yarra Valley To Healesville is for the YVTR and I want them to have all the success they can have. Promoting it for tourists, wine and food tasters and families is something that needs to be done.
You could provide an hourly service to Yarra Glen with a Vlo/sprinter to funnel tourists to the valley, something i would do with the service stopping at Richmond, Camberwell, Ringwood, Lilydale and Yarra Glen.
Metro to Coldstream with a massive stabling facility, is the only chance Metro will go beyond Lilydale. There may be some demand but you would need Park and ride facilities as well as frequent bus services funnelled into Colstream from Yering, Kinglake, Lilydale Airport and Yarra Glen to justify it. Then maybe extend the yvtr to Coldstream similar to the puffing billy at Belgrave
In terms of bringing tourists into the valley, one of the main reasons is to visit wineries and restaurants. This ideally requires a car, or a winery-tour bus, so they wouldn't be coming by train anyway. And the existing PT bus provides a much better service than a train could. The stops in Yarra Glen (two of them) are much more conveniently located than the station, and the same is true at the Healesville end, where you also have some services extended to the sanctuary, and others running directly down the highway to Lilydale.
Run a Vlo/sprinter? There would be pathing issues to run it as described, particularly if/when the 20 minute headway to Ringwood is introduced (already running at weekends, probably the most popular time for tourists), but a DERM used to run a similar service from Lilydale. It closed, due to a combination of poor track, expensive maintenance, and even poorer patronage.
If the YVTR, once up and running between YG and Healesville, is to attract tourists, they could come by train to Lilydale and then use the bus, or more likely come by car, park at one end and do the return trip - or use the bus to go back. Lack of a train service from Lilydale would not be a problem, but in any case the provision of one is just not feasible.