Where can you join a STAR & STAR Altitudes?
You can only file, and ATC can only assign, one of the listed transitions. However, that doesn't mean you will actually fly it as charted (unless you lose comms). If you filed lower than the charted altitudes, you are not expected to climb. In practice, ATC mau give you direct a later fix (e.g. FZT) where you'll join aircraft descending to your level. Or, if you're slow, they might put you on vectors off the STAR to keep you out of the way of faster traffic. It all depends on what else is going on around you, so it's difficult to predict what will actually happen.