I don't know if it will be useful, but just in case I pass you this general information:
Any citizen of the European Economic Area may remain in Portugal for a period exceeding 3 months, but must apply for the "Certificate of Registration for EU citizens" in the City Hall of their area of residence.
Monte Sahaja corresponds to São Martinho das Amoreiras that belongs to the City Council of Odemira.
Those who live in Montse Sahaja throughout the year will be registered in Odemira, as residents of São Martinho das Amoreiras. I don't know if they are public data, but if they were, the statistics would show the nationalities of those who live in São Martinho das Amoreiras. You can ask in:
Municipal Chamber of Odemira
Praça da República
tel +351 283 320 900 fax +351 283 327 323
The population of São Martinho das Amoreiras in the 2011 Census (INE) was 1006 inhabitants. Suppose that according to the article of El Confidencial that you published in the Forum, 200 people live in a stable manner in Monte Sahaja throughout the year. If we discount the Portuguese who live with M., who do not know how many they are, you can find out the nationalities by the registration, although those who do not have European origin should look for other tricks to be there all year.
The law in Portugal allows the residence to foreign citizens for humanitarian reasons, of national interest or public interest for the exercise of a relevant activity in the scientific, cultural, sports, economic and social field.
I do not know if the Associação Mooji Sangha is considered as exercising a relevant activity in the social field...
Maybe someone who speaks Portuguese can make some calls to the town hall of Odemira to inquire.