For me it would be great to run a special File Action for "*.sublime-project" files just by pressing enter, without explicitly selecting a File Action using right-arrow or a workflow prefix.
Description:
1. find a ".sublime-project" file using the normal fuzzy File Search
2. hit enter
3. run my custom sublime File Action / workflow
Alfred can already move your custom File Actions to the top with "Sort action by last used per file type". An extra checkbox for implicitly executing the top-most action just by pressing enter is maybe enough to enable this feature. This is helpful when using Alfred as a cmd+tab complement to switch between open files and applications. Example: Switch to chrome: "chro...[enter]", then switch to a sublime project: "myproj...[enter]". (The latter would run my custom workflow.)
Kind regards, Carl
PS I have found a workaround by changing my "*.sublime-project" files in OSX to always open with a home-made application running some additional scripts when these files are opened.