Refiling PPA of a non-disclosed invention after 12 month - are any changes required?

Question

Let's assume I have missed the 12 month term and haven't filed neither regular patent nor national patents via PCT. The invention was disclosed only under NDAs during that time.

1. Is it legal to just file the exact same PPA again and refer to the second application during regular patent application and PCT national patent applications? I.e. will patents be granted if the patent offices (US, and others) will know about the first PPA?

2. If #1 is not legal/possible - can an addition of a narrow dependent claim be interpreted as a new, separate PPA and referred to in US/international PCT filing?

3. If also #2 is not legal/possible - how different should the second PPA be?

4. If #1/#2 is legal/possible - what if I indeed file a second PPA on month 16 and then regular patent based on the second PPA on month 27 but it turns out that somebody has stolen my idea and filed a patent on month 8 after my first PPA.

   4.1. Will I be able to disqualify the thief using my first PPA?
   4.2. Can this have negative impact on my own patent?

Answer 1

First, the 12 month deadline was traditionally very strict but now you could file a non-provisional up to month 14 and petition to have the benefit of the provisional be validly claimed as long as the delay was unintentional.

1. You can absolutely refile the exact same provisional application at month 16 or any other time. This works because you have not made the information available to the public meanwhile. For the US, there are caveats involving public demonstrations even if they don’t disclose the invention, and offers for sale even if they do not disclose the invention.

Under these circumstances you do not get a priority benefit under the Paris Convention from any later filed applications so you need to keep it confidential until you file everywhere else in the world you intend to file and are subject to someone publishing, or beating you to file, an independently developed invention.

Of course if someone has invented the same thing and filed an application between your two provisional filings you will be out of luck.

Someone beats you to filing with their own invention and you lose, the US is now a first-to-file jurisdiction. There is a process to contest an application from an applicant you believe derived (stole) from you. However there have been very, very few derivation proceedings initiated and almost none have been successful which is outside my expertise and experience.

As pointed out in a comment by Eric S. you could presumably sue them to attempt to force them to assign their application to you or to abandon their application. As a retired patent agent I can be confident in my answer relating to patent law at the USPTO but not to suing in court.