printToFileAsync always writes a generated file name, so an app that wants a meaningful PDF name (an invoice number, a report title) has to copy or move the file afterwards.

Request: an optional in the options, on iOS and Android. A name is accepted only if it is a plain basename ending in (^[A-Za-z0-9_-]+\.pdf$), the file is written to the cache directory, and the call fails when the destination already exists. When is omitted the behaviour is unchanged.

I opened a PR with this: https://github.com/expo/expo/pull/52624 (the earlier GitHub issue, https://github.com/expo/expo/issues/52621, was closed by the triage bot as missing a repro, which does not apply to a feature request).