The idea is simple enough. My concerns would be how many resources it would use after a while of use. It's basically duplicating your already existing history.
Dash is great combined with Alfred. I changed the keyword to a period (.) with no space so lookups look like ".extend" and bam I get the results for extend from four docsets.
| <- 0 1 -> | <- 1 2 -> | <- 2 3 -> |
That makes more sense.