Hi Scott,
I am not aware of a way to do that. One way that may help
1) create N >= 4 tasks. Make sure the N tasks can run sequencially by setting up min/max resources units.
2) Add a dummy task TaskD after Task A that'll sleep for X seconds. e.g. X=10 seconds.
3) Write a program that will check TaskA's status while the job is running TaskD. Then modify the task's dependsOn property so that either TaskB or TaskC can be the dependencies of taskA, depending on whether taskA is success or fail.
Hope this can help
Liwei