I've tried it.
Four packages is needed before the workflow can work:
bundler, plist, alfred-workflow, rb-appscript
Also I've made an small modification on your script to make it work with the time tracking app Tyme:
on alfred_script(q)
tell application "System Events"
if not (exists process "OmniFocus") then
tell application "OmniFocus" to activate
end if
end tell
tell application "OmniFocus"
set my_selection to first item of (parse tasks into default document with transport text q)
set tsk to name of my_selection
set due to due date of my_selection
set esti to (estimated minutes of my_selection) * 60 as real
set proj to name of containing project of my_selection
tell application "Tyme" to make new task of (project proj) of application "Tyme" with properties {name:tsk, plannedDurationHours:esti, dueDate:due}
tell application "Tyme" to make new taskTag of task tsk of (project proj) of application "Tyme" with properties {name:"Incomplete"}
end tell
end alfred_script
If you are interested in use omnifocus with fantastical and tyme, here you go: https://github.com/fuxialexander/Applescript
