Thanks, Geoff. Do note that my post above was not to take issue with your distinction; I was querying the upper-case concept.
Although, personally, I don't even believe that there is a/the Thai forest tradition. It is my belief that there are several Thai forest traditions, with very different approaches to monastic life. Ajahn Mun's and Ajahn Chah's legacies just happen to be better known in the West because of the Net, but those of us closer to the scene see a much greater variety on the ground.
To bring up in stark contrast one such difference, let's consider Ajahn Chah's and Ajahn Mahaboowa's attitudes to what I conveniently call "amulets". The former is famous for having nothing to do with these things, but it appears that the latter did not have issues with sitting in at "phuttaphisek" (Buddha-abisekha) ceremonies for these momentoes.
On the subject of study, even within Ajahn Mun's "lineage", there were a merry minority of monks who studied, even Commentarial material. One such example was Ajahn Thate. The other was Ven Thanissaro's teacher's teacher, Ajahn Lee.
Even geo-politics have left their mark on the "Thai" forest traditions. The Killing Fields led to a large influx of Cambodian monks into the eastern borders of Thailand. I personally know one such practising forest monk, and surprise, surprise, he's also an Abhidhammika.
You do realise, of course, that "Western Forest Sangha" is an ex-Vinaya concept, given the Buddha's prohibition against over-sized siimas. I suppose they do realise that, since a super-sized "sangha" would require a communal confession of the faith a la Nicean Creed.