Last night I have made a new cell for my Cheapy-ERF, the former mechanism is better, more elegant and secure, but this new one is aimed as a prototype of an alternative concept - in order to remove the internal reflection.
Since the internal reflection is pretty strong, I believe if the tilting is effective, the overall image quality will improve significantly, the contrast will be much better and I believe it can be readily seen in the histogram of the image capture.
So far it's sunny, and I believe that I'll have chance to test it today.
Once the design is proven, I will try to find someone to make a more permanent and secure setup... right now it's based on a $3 cylindrical plastic box and a lot of duct tapes only, have to be extremely careful when used.
1316 (GMT+8): it's very cloudy now, essentially a total covering, however, I still setup the C5/PST with tilting. During some short breaks when cloud got thinner, I actually saw the same internal reflection. Therefore, it's not about the ERF, I tilted up the whole ERF by at least 15 degrees, but it's the bright secondary shadow was still there, so this route is not viable.