Folder action delay until done

Question

I run a video encoding software called Episode Engine, and what it does is while encoding a video, it kicks out a temporary file in the output folder with a file size of 0. It does not actually update the filesize until encoding is complete.
What I want to do is set a folder action to an output folder (which receives up to 5 videos at a time from encoding) that uploads the file automatically to a Transmit (FTP Client) favorite. I also want to account for the fact that I may drop large files in this folder as well, which could take time, but dont stay at 0 file size until the transfer is done. The part I'm having trouble with is delaying the transmit action until the file is done encoding. What I currently have does not work. And I dont know any way to monitor a folder action workflow, so I'm not sure where it's failing. Any recommendations?
p.s. We're still running 10.6.8 on this computer (I know, I know...)
property DELAY_TIME_SECONDS : 5 -- How long to wait between checking file size.
on adding folder items to thisFolder after receiving theItems
     repeat with f in theItems
                         set currSize to 0
                         set oldSize to 0
                         set newSize to -1
                         repeat while currSize is 0
                                        delay 2
                                        set currSize to size of (info for f)
                         end repeat
                         repeat while newSize is not equal to oldSize
                                        -- Get the file size.
            set oldSize to size of (info for f)
            delay DELAY_TIME_SECONDS
             -- Sample the size again after delay for comparison.
                                        set newSize to size of (info for f)
                         end repeat
     end repeat
end adding folder items to

Answer 1

Folder Actions has some built in support for recognizing 'busy' files, but it's not too intelligent.  It works well with Finder moves and copies, not so well with other things.  There are three ways I can think of to solve this problem.
Tweak your script with a test for temp files so that it skips them.  This may cause secondary headaches (e.g. you skip a temp file, but Lightroom finishes the job in the ten second throttle period so the creation of the the file(s) you want to move is missed by folder actions), but there's no way to tell unless you try.
Drop Folder Actions and set up a QueueDirectories launch agent.  This would wait for items to be added to the folder then move and delete them - you write the script to idle until temp files are done processing.
Forget about immediate gratification and write a LaunchAgent that will sync the folders hourly using rsync.
Which would you prefer?