rather than rely on a torque spec or tool of unknown reliability, why not apply a functional torque logic. You're not dealing with an aircraft engine bolt which might vibrate loose unseen and cause a crash.

It's a bicycle seat clamp whose sole job is to keep the post secured. Tighten it until it feels tight. Check by trying to twist the saddle. If it seems OK ride it. If nothing moves you're in, if the seat moves tighten a bit more. Once the post is secured enough to meet your needs any tighter is needless strain on the parts.

This procedure is not appropriate for a professional mechanic working on other peoples bikes and so a pro would have to develop good consistent hand skills, but for anyone working on their own equipment "good enough" is good enough.