Hey guys,
I just released another one of my tools,
StarBright, which could maybe of help.
It trades resolution for longer exposure times, but never over-exposes any part of the picture (it does automatic HDR compositing). It was specially designed for people like you and me, who have resolution to spare, but can't rely on longer exposure times.
Even if you don't have resolution to spare, it can still be of service.
Unlike StarWipe, I don't have a manual yet (it's a pre-release for now), but if you get stuck, drop me a mail or PM.
If curve manipulation starts giving you banding/noise or contrast starts to suffer, give StarBright a go.