I've been trying to do this. I'm currently lvl 4 and every time I look for a group, I get invited to a train with mostly level 15-20 players. Which is cool, but it means I spend a lot of time dying just to get to where everyone is. And then during the fights, my contribution isn't weighted as heavily because I'm such a low level. In two days of doing this I've managed to get one level.
The only time I've somewhat enjoyed Eureka was when I was invited to a low level group and we just farmed low level mobs for like an hour. I leveled up twice and got 11 crystals. THAT'S what I need to be doing. Trains are only fun when you're higher level. But I need crystals for gear.