Hi gyrus, thanks for the feedback. The biggest motivation for building this plugin is to provide an easy way for less technically-knowledgable users to build section-specific widgets (such as showing a RSS feed from a movie review sites for posts in the "Movies" category). Therefore, my top priority is to deliever a reasonably clean and easy to use interface that can address those needs. Building the functionailty you proposed into the plugin would probably make the UI more complex than it needs to be - yes I know I'm quite picky ;) The bottom line is, I simply don't think there is a big enough need for that to outweight to extra complexity added to the UI. I could be wrong though, so if you can think of any legimate use cases for that feel free to point it out.
As for the Widget Logic-style conditional code, I'd strongly retain from doing because 1. it's a potential security breach; 2. it's far too complicated to be useful for my primary target users. More importantly, this plugin is not meant to be a replacement for Widget Logic - although I haven't tested it personally, I believe this plugin should work with Widget Logic without any problems, so if that floats your boat, you can always use it in conjunction with Widget Logic.
That being said, the plugin is fully open-sourced and GPL-compatible, so if you disagree with me or you have a smart idea then feel free to modify and extend the plugin. And of course, if that proves me wrong, I'll be more than happy to merge that code into the next version of the plugin!
Thanks again for the feedback - really appreaciate that!