I don't think u can compare svdk and sabarimala.
Don't think all train bound svdk are for pilgrimage purpose but sabarimala is purely or mostly for pilgrimage ppl.
And those going to sabarimala won't prefer to travel In ac or luxurious mode of transportation.
We can't tell about timing as because the rush there is really big.
Timing...
more... not a problem but ac.....I doubt it.