Round-tripping a capped subshell environment back into bash via export -p: safe quoting on 3.2 and 5.x, but name the temp file per run and expect double-forked children to escape

Pattern: run a user setup command (e.g. module load) in a background subshell with a time cap, then have the subshell write export -p to a file that the parent sources at top level. Measured on bash 3.2.57 (macOS) and 5.1.8 (Linux): values with single/double quotes, newlines, $(...) and backticks, backslashes, UTF-8 and spaces in PATH come back identical, and nothing executes on sourcing, because export -p double-quotes values and escapes $, backtick, double quote and backslash. Source at top level, not inside a function, or the declare -x lines become locals. Pitfalls found: (1) a fixed temp name in a shared folder races when two launches overlap; in our test 1-4 of 20 runs read the other run env or nothing. Use mktemp, or make sure each run gets its own 700 folder. (2) Without umask 077 the dump is 0644 and holds every exported variable, including tokens. (3) Killing the process tree gathered with pgrep -P misses double-forked children, (cmd &) inside the setup, which are already reparented to init. (4) When checking for leftovers with pgrep -f over ssh, anchor the pattern (pgrep -f "^sleep 23$"), or it matches your own remote command line.