When travelling to one’s home country, or an EU national travelling within the EU, they only need the PP to be valid on the day of travel. So up and including the expiry date.

I have worked with the police in Spain for 20 years. From time to time people report the loss of their PP. If there is insufficient time to obtain an emergency travel document from the consulate, they are usually permitted to travel using the police report and other ID which is acceptable to the person checking it on the day of travel.

But I still have the question about a Filipino National entering RoP on a non Philippines PP I cannot believe they can be restricted as to how long they can stay.

PS I have not suggested a person would be allowed to travel without a valid PP or proof they had one, (as when it was lost).

PPS Presentation of an expired RoP PP I would think proves one is a RoP national, thus entitled to entry RoP without any formality and stay for as long as they wish, including forever.