When moving from 4->3 they become [0,0,1].
When moving from 3->4 they become [0,0,0,1,0,0].
Clicking 'reset' or manually changing the w slider to [0,0,0.5,1,0,0] results in the expected animation.
5: q1q4 = 0.5, q2q3 = 1.0, rest = 0.0 5->4: q1q4 = 0.5, q2q3 = 1.0, rest = 0.0 4->3: We no longer have the q1q4 plane available therefore q2q3 = 1.0, rest = 0.0 3->4: Now we have the q1q4 plane back but the state has been cleared from previous interactions Going to a lower dimension essentially deletes previously set state of higher dimensional planes because they don't exist at that point.
When resetting it just goes back to the default configuration.