Setspin

Setspin is a TSS -> TST Tower opener created by 10Penta. There is a more than 99.2% chance of executing the TST Tower on the 3rd and 4th bags, much higher compared to most other TST Tower openers.

First Bag
The first bad has a 63.3% chance to stack the first bag including the mirror, and a 43.3% chance not including mirrors.

Second Bag LJOS
For the second bag, the LJOS is always placed the same way, while the ITZ needs to be placed differently depending on your bag. The LJOS is always placed as follows (the LJO rectangle may need to be flipped depending on whether L or J comes first):

You may need to use hold.

Route 1 Z<T
The first image can always be built, but the second and third may result in a flatter stack:

Route 2 T<Z
Here, you simply want to place all your pieces except for the S like this:

And place the S piece somewhere, depending on the piece order. Below are some examples. This will always work unless you get an very early T and S (TS<IOJZ). If this is the case, there will be nowhere good to place the S.

Dealing With Early S
As mentioned above, if the S piece is too early, the setups above are not possible. There are 2 things you can do:

Alternate T<Z Setup
If you also get T<I, then changing the position of the I piece allows the 3rd bag to always be built:

Waste T
If none of the above setups are possible, your best choice is to waste T: