Buddhism and the groundless ground

In this IPS thread Balder linked to a David Loy video. After listening to the first few minutes a couple of comments. He starts by noting that Buddhism's defining characteristics are impermanence and co-dependent arising. (I'd even call these characteristics of postmetaphysics, in that there is no utterly transcendent, permanent or unchanging anything.) Then he discusses how Buddhism must itself exemplify those characteristics when it enters new cultures. Hence it syncretized with Taoism in China and with Bon in Tibet. However if in the syncretization process it takes on characteristics that are not impermanent and/or co-dependent arising then it cease to be Buddhism per se. It could be a mix of Buddhism and something else, part of each, but it loses that essenceless 'essence' or groundless 'ground,' at least in some respects and contexts. We see this is kennlingus, for example, which mixes Vedanta and Buddhism and thereby the model has both elements of metaphysics and postmetaphysics.