Idea for a new prop red dot sight...
If you got some thin acrylic, only ~4mm thick (the clear colourless plastic kind) and a small laser pen inside the gun, you could have the laser shine up to a small point upon the acrylic. Or, you could adapt on this and have a very small laser unit on the base of the RDS (where it would clip onto the rails) hidden of course,and have it shine on to the acrylic.
The one thing that I hate about the RDS is that you only have one bearing point. I don't see how it would aid you in any way, because one dot isn't enough to aim with. You would have to line it up with some other sight.
Something which could work is an ACOG (advanced combat optical gunsight) where on each of the lenses is a bearing point which you could line up.