Cyclododecane spray looks like a good way to protect a valuable article during surface evaluation / transportation. The spray is a bit expensive (>$50) and seems to be limited in availability in the U.S. Any solid that sublimates I put into the general category of "magic". As a kid if I happened to get a chunk of dry ice, my entertainment agenda was set for the rest of the day. The last bit was typically reserved for dry ice hockey on the kitchen table.
I did try a crude cornstarch test but not on the DPDLX but instead on the extra fiberglass dome I have (which was identified here to be a Portumac recast). I dusted the right half of the dome with cornstarch. A finer dusting would have been better, but the results below do show that this does improve the ability of the AutoDesk 123D Catch algorithm to identify trackable features and to ascertain the shape of the dome better (well, plus the globs of cornstarch). It also rinsed off easily with water with no apparent scratches to the surface.
This was done outside on a cloudy day on a textured glass table top. Putting newspaper print on the table surface would probably provide more discrete points for tracking and reduce the "Philadelphia Experiment" merging of the dome with the table top.