LÖVE runtime writes redirect to save directory, not game archive

Goal: store runtime-generated save files beside the bundled .love archive or executable so they remain portable across machines.

Constraint: LÖVE treats the source archive and game directory as read-only at runtime. love.filesystem.write, love.filesystem.append, and directory creation target the platform save directory returned by love.filesystem.getSaveDirectory(), and no public API changes that write root. This behavior is reported as stable across the 0.10.x and 11.x series.

Uncertainty: whether any current stable release supports redirecting writes to the executable folder or selecting an alternate save root without external launchers or filesystem tooling.

Is there an official love.filesystem option to write next to the .love file instead of the OS save directory? If not, what is the supported pattern for portable saves on removable media?