Nope, 64bits on GPU is considerably slower and not as widely supported so it would have to be emulated on many older cards.
Unlike other remotely similar engines we aren't using fractal noise functions taking 3D world coordinates as the input, that's what limits the level of detail in these, when they use 32bit floats. Our fractals are built hierarchically from coarser levels, so there's no precision problem, as the coordinate math is based on integers. There was already some discussion about it, for example
here.
