Unorthodox Line Clears

In games with recursive gravity that reward cascading line clears such as Tetris Worlds and Quadra, certain line clears discouraged in naive gravity become favorable.

Reflection
A three-cascade example:

O Replacement
Due to the nature of the O tetromino, the mirrored line clear formation is the same for both the S and Z tetrominoes.

J/L Replacement
The T tetromino can be used in the following situations where only the L or J could be used initially.