I regularly catch the train from Upwey to Box Hill, getting to Box Hill at about 7am. The train is not too full and I always use the rear carriage rear door. Often there is one other cyclist already onboard and another that gets on Heathmont. Never had any troubles so far.
In the afternoons I go to either Box Hill, Laburnum, Ringwood or Bayswater (depending on time, daylight and how I feel). Regardless of where I get on, I never have a problem in the rear carriage and more often than not bump into other cycling commuters. I usually get the homeward bound train around about 5pm and it's never chock-a-block in the rear carriage. Much later than that and I don't think I'd have too much of a problem either, because by the time I get on the train it has already delivered many passengers to their destination. The bonus of riding that bit further out!
On one occasion (so far) I did ride all the way home to Upwey from Abbotsford. That last stretch from Upper Ferntree Gully to Upwey was almost the end of me

I'll try it again when the days get a bit longer
