This is a very neat and novel idea!
Recently I’ve been trying to find a good way to do find-and-replace in Chrome, but I didn’t find the Chrome extensions to be very flexible, especially when I wanted to do find-and-replace on text selections.
I love this workflow because it’s like a one-size-fits-all: not only is it a good tool for Chrome, but it's also good for any Mac application since I can access Alfred from anywhere!
I guess the only downside is that it requires the clipboard, but that isn’t a big deal for me since I have Alfred’s Clipboard History configured as well.
If I may suggest, would it be possible to support the tr/// operation as well?
Thanks so much!