Swanboat is a Wall STSD opener created by Winterfrost. The first bag requires an early S, O, and J.
Third Bag, I before Z
This path is the cleanest option when available, requiring I to come before Z to stack.
Afterwards, you can always stack a Trinity.
Third Bag, L before S
If Z comes before I, this can be used in conjunction with the S before L path to cover all queues.
Below is a possible way to guarantee a 4th bag T-Spin Double.
Third Bag, S before L
This can be followed up by a T-Spin Triple or regular stacking.