Do model watermarks (as left by Maya or 3D Studio Max) remain in the model even when they've been converted into the .jme format?
I don't know, but I was under the impression that they watermark the renders not the models?
I suppose the watermarks are stealthed inside the model geometry data? In that case, unless you apply some kind of unusual transformation they will stay. Also if the model is exported into textual/non-binary format, the floating point values may get truncated and the watermark will be harder to read.
I am not an expert on watermarks so I can only guess, but as the people who make them create patents and get paid millions I expect the watermarks to be more persistent than anything else there is…