A single fixed path for the temporary input file means only one copy of the converter can run at a time (unless it's in a sandbox, which wasn't clear from the context). A PID specific tempfile or, better, use a standard 'make a new temp file name so there's not a collision' utility, would allow parallel conversions.

> Someone could potentially use the underlying tools directly in their own needs workflow, or an expert in those tools could mention if there's a vulnerability / common mistake pattern.

Yep, that's something we cover in our about page. We process the untrusted document in a gVisor sandbox, that runs within a hardened Linux container, that runs within a Docker Desktop VM (in Windows/macOS). And yet, that doesn't mean that Dangerzone can't get hacked by a determined (possibly state-backed) attacker. So yeah, you have a point.

At the same time, using tools like this raises the "you must be THIS determined to enter" bar. This means attackers must spend much more money, time, expertise, 0-days, etc. These resources are finite, so more people are protected as a net result, even if we can't protect everyone. That's the way I see it at least.