Namaste
Actually, I know quite a bit about them, but it would be inaccurate to link the Swami who is an American, and Sree Maa who is from Assam to some of the traditions mentioned in this thread.
Sometime in the late 70s or early 80s perhaps I recall visiting their Mandir on occasion, it was in the San Francisco Bay Area, I recall driving up a rather steep drive in an upper class area of either Moraga or Orinda in California. The house which was the mandir was in a very nice location, inside on the temple altar were a large number of Devi murtis, six primary ones as I recall with Kali, Saraswati and Lakshmi as focus, they appeared to me to be made out of some paper mache like material (though I am not 100 percent sure of the material but it wasn't metal, nor clay as used during Durga Puja Festival), probably six to eight such murtis some about 4 feet tall and brighly painted with gouche type paint. They were Chandi centric, Devi centric.
They later moved to a small building in Martinez California. I had lost track of them after they left the former site, I had visited their temple infrequently. But then one day I was in a shopping mall sitting in a rest area when a man older than me plopped down next to me specifically to chat. He knew I was a Hindu (it was my Indian style shirt and simple sandals I was wearing), and he earnestly wanted to befriend me. He invited me to the Devi Mandir in Martinez. I am a temple touring fan, I gave him my phone number since he was going to meet me there and "introduce me to the Swami", but his feelings were hurt when I didn't show up. I felt bad when he called me up, so I agreed to go visit at his home address, then he took me to the temple.
I was surprised to realize this was the same mandir as at the original location, the Swami spoke with me and my host, then there was a puja and me and the host were the only guests on an evening work night. Later, I visited a few more times including later with my wife. I got to know the Swami but to a lesser extent Sree Maa (who I think was his wife or someone he followed, frankly I never asked him). But then they closed down that location and moved yet again to Napa California. I visted that location in Napa only a couple of times with my wife.
Many years later, in fact it might have been a decade later or more, just 2 years ago I made my first journey into "internet Hinduism" on a Hindu forum before I joined this forum. A member joined that forum, a young man with black hair and glasses (I will explain how I knew this in a minute but oddly I cannot remember his name anymore), and he was an ardent (but perhaps newbie) advocate of the Devi Mandir, the Swami and "Maa". He started to ask me to visit their website and join in on "onlibe live satsang with the Swami". I said I would check it out.
But when I created a member id and signed in for the online "class" and interactive discussion with the Swami, though my member name would display during the live session, and though I could see IMs, the "video" (some sort of webcam pointing to the Swami and altar) along with the audio would not work. I could see nothing, nor hear nothing, but IMs kept popping up welcoming me from the young new and ardent follower (his personal picture was his avatar) and one other person. They apparently thought I was fully online, but their technology wasn't working. It sort of turned into a disaster of sorts, apparently while I was replying "I cannot see anything, the video or audio isn't working" I didn't realize I was sending these to the Swami as "questions". Anyway I finally just closed the webpage.
I apologized to the boy later via an IM on the other forum, trying to explain that the video would not work. He suggested some "fix" but the exact same thing happened again about a week later. To make a long story short, I figured out that these sessions would not work on Microsoft Windows (the newer version I was using), but only a Mac, and there were no drivers to make it work on Windows.
So I gave up. But I mentioned to the boy I might visit the Napa location in the summer (but I never did).
Then about a few weeks later, I tried from someone elses computer, a Mac. It worked, and I asked a question to the Swami under my member name, I don't recall the exact question but the lecture before the Q&A was about Jyana Yoga and moksha, so I asked to the effect "Can't someone also achieve moksha by Bhakti Yoga?"...
I am not sure what set off the reaction, but it appeared this got the Swami a bit angry at me and he shouted at me "No!" and something other, then he repeated my member name as if he knew me but was not happy... hmmm... I suppose if he realized who I actually was from the past, it might have benn different. I tried one more time about a week later and asked about caste, but no answer was provided in response and the next time I checked out the website the entire format of Q & A was shutdown.
The Swami is an American who started roaming about India during the 1960s. He would apparently associate with Sadhus, often in the hilly areas. He might have been involved in Tantrika, but then he found the "Chandi Path" and some aspects of the Devi aligned with some Sadhus who would engage in tapas and such. He later met with "Maa" who is from Assam and who represents Devi within this mandir, he never would mention who his guru was but apparently he was initiated by Swami Amritananda Saraswati, and a lineage of the Dashnami Order.
The American Swami is a very nice Swami, if one has a chance to visit Napa they should stop by.
Om Namah Sivaya