One "typically TS application" that would definitely present an issue is the connection between a guitar with active electronics and an effects unit (stompbox).
The output of the guitar and the input of the stompbox almost always have a TRS jack that is used to power the device on:
One battery terminal (usually negative) is connected to the Ring terminal of the jack so that when a TS cable is inserted, it shorts the Ring and Sleeve terminals to connect the battery to the ground in the electronics.
Putting a TRS cable between two such devices connects their batteries together through the "floating" Ring conductor, with unpredictable results (and possible damage).
Using a TRS from an active guitar to a "universal" input (like on some audio interfaces) designed for either unbalanced TS or unbalanced TRS may apply battery power to the interface unit. It's probably blocked by a capacitor so as not to cause damage, but this is not guaranteed. The guitar electronics are not likely to power on.
Using a TRS cable between an active guitar to an amplifier or between a passive guitar and a stompbox may work, but is not guaranteed.