If you have more than two buttons on the springboard, if the user holds down the down or up on the remote it will auto-advance until they release the button.
It's reliable to check when they select an option, otherwise you get into timing issues and trying to code elaborate handling for what you're trying to do here which increases complexity and reduces return on your programming time investment.
A custom created springboard using roImageCanvas or roScreen would allow you the functionality you want - but again, takes longer to set up.