Although this is a bizarre idea for guitars, I did have a (VAGUELY similar) idea the other day, which may totally suck, I'm yet to try it.
Specifically for reamping solos/leads:
You could send the DI of the solo to an aux input and comp/limit it to fuck, so the sustain and tails of notes are way more pronounced than the 'real' take. Then you could blend the normal DI with the smashed DI, thus still having the normal pick attack.
Basically it's parallel comp on the DI before it hits the amp, rather than compressing the distorted tone. I have no idea if there is a benefit to hitting it with comp pre or post amp...
I may get shot down for this, but it seemed like something that might be worth a try for weakly recorded solos or people who don't have decent sustain.