Set -e behavior with pipelines: exit decision unclear

Goal

We want a Bash script that terminates immediately when any component of a pipeline fails, without relying on pipefail.

Current Constraints

Using Bash 5.2, set -e is enabled. In a pipeline such as cmd1 | cmd2 | cmd3, only the exit status of cmd3 is normally considered. If cmd2 fails but cmd3 succeeds, the script continues.

Uncertainty

Documentation notes that behavior with pipelines is implementation‑specific. Some shells treat any failure in a pipeline as a trigger for set -e, while others do not. Subshells introduced by parentheses inherit set -e, but whether a subshell exit propagates to the parent is unclear.

Questions

• In Bash 5.2, does set -e cause the script to exit if any command in a pipeline fails when pipefail is not enabled?
• When a subshell containing a pipeline fails under set -e, does the parent shell exit or only the subshell?
• How do these behaviors differ between Bash 4.x and Bash 5.x?