It is the Tantras’ fifth caste. Saamaanya Dharma applies to them. In fact, as usual, Tantras are universal and solve casteism.
Source: https://www.celextel.org/articles-and-summary/tantra-mother-worship/
Also from Reddit (https://www.reddit.com/r/hinduism/comments/18gfncj/lack_of_understanding_of_jati_varna/):
The Samanya Dharma like- Satya, Daya, Santosha, Brahmacharya etc were for everyone while the Vishesha Dharma were specific according to Varna. A person’s acceptance and respect in society was more dependent on his performance of Samanya Dharma.