Of course you can't "have" RescueTime implement a certain feature, but you do have clout at y-funded companies, right? I mean, it's in your best interest to push the funded companies into success by suggesting new/complementary features.
The time-suck industry will be an interesting one to watch; I can see why you chose to fund 8aweek. The major problem I see with using a toolbar is that the time-suck, in many ways, is due to internet addiction. And if it's easy to bypass the toolbar, it might not be very useful. Addiction usually wins. Noprocrast fails in that regard, because you can simply launch another browser.
Can anyone share how much they ignore noprocrast?
If you have enough personal responsibility to obey noprocrast/toolbar restrictions, I can see how this would be awesome. But I also think that market is probably small. Snooze is obviously the way 8aweek tries to get around this, but after a while I think it might get annoying. I'll try it, though, and see how it goes.