Doctor M said:

While I've never played with it (or understood it completely), Tweak() has a MaxSat and MinSat that can let you cap the range that the Sat option effects. http://avisynth.org/mediawiki/Tweak

I'm thinking that by utilizing those options you could in theory increase the saturation (for all colors including the lower range reds) but avoid making the bleeding any worse.

Is anyone familiar with this?

Wow, nobody? I guess I'll have to find some time and mess around with it.