What timeout mechanisms does openSUSE systemd apply during service cancellation?

Timeout handling ambiguity in openSUSE systemd

Developers need clarity on which TimeoutStartSec and TimeoutStopSec values are enforced when a service receives a cancellation signal or exceeds its allotted time, especially given distribution‑wide defaults and per‑unit overrides.

The effective timeout depends on the combination of the unit’s explicit settings, the distribution‑level DefaultTimeoutStartSec, and potential differences between openSUSE Leap and Tumbleweed systemd releases.

What specific criteria determine the precedence of TimeoutStartSec versus DefaultTimeoutStartSec during a SIGTERM‑initiated cancellation? How does systemd resolve conflicting timeout values when multiple configuration layers apply?