Now the thing is, for my player animation design, pressing up on, say, the left thumbstick does a different movement or action depending on which state you're in. For example, when you're stood on your snowboard idling, pressing the left thumbstick forward makes the player shuffle along to start moving. When the player is jumping, pressing the left thumbstick makes him tilt forward, and so on.
A state machine works this way: One of its states is active. On each update of the state machine all outgoing transitions of the active state are investigated whether their conditions are true. At most one transition has to be chosen. If none is chosen then the state remains active, otherwise the state which is referred by the transition is the next active state. The condition is a boolean expression.
With this in mind, each of the states "idling" and "jumping" (taken from your post above) have their own transitions, and hence their own conditions, and hence may have different following states. Moreover, due to the separate states, the input configuration can bind one input trigger to different variables.
So a state definition like your example would be:
<state name="idle_board_on" initial="true">
<transition name="idle_board_on-shuffle_forward" triggeredBy="shuffle" follower="shuffle_forward" />
<!-- here more transitions outgoing from idle_board_on" -->
</state>
<state name="jump_board_on">
<transition name="jump_board_on-tilt_forward" triggeredBy="tilt" follower="tilt_forward" />
<!-- here more transitions outgoing from jump_board_on" -->
</state>
<!-- here more states -->
I don't see a problem here.