I think “unlimited” is a way too big word considering all the limitations, I’m not even sure what’s left after these:

Unlike Germany’s identically priced travel pass, however, the Portuguese ticket is not available on buses or on intercity trains such as the Alfa Pendular, Intercidades, InterRegional and Internacional services.

It is also not valid for urban networks in Porto, Lisbon and Coimbra.

Where is Portugal’s €49 rail pass valid? The new national train pass can be used on most regional services around the country, but there are a couple of excluded areas.

Both the Alentejo Litoral and the Coimbra area are not participating in the scheme.

This means the pass is not valid on routes including Régua-Pocinho (Douro Line), Coimbra-Figueira da Foz (suburban Coimbra), Pinhal Novo-Évora and Pinhal Novo-Vila Nova da Baronia (Alentejo Line), and Pinhal Novo-Tunes (Southern Line).