Please, if you modify shaders, call them something different, or we'll end up with horrible compatibility issues (it'll probably crash if you make an event setting an effect parameter, and send it to someone with the non-modified shader).
The problem with that modification is blur intensities less than 1 waste processing time, because more samples than necessary to achieve the effect are made. Above it and yes, you get weird aliasing errors. That's why there's been no blur intensity built in. It's possible to do a cheap, quick blur, which is *much* faster than the blur shaders (atm theyre the slowest shaders), but I need to make runtime modifications to make it possible.