Opening a RFC for this comment in #3711 which is a specific issue of wanting the underling task exit code to be returned by turbo.

I want to exit with code zero if and only if the process is able to exit gracefully with no issues. For that reason I want to trap '' instead, propagating the exit code.

#3711 (comment)

For example a task could return a 1 if it shut down successfully or a 2 if it wasn't able to clean up all resources.

turbo obviously could not forward all exit codes, but I think returning the maximum exit code still could be useful.