I'm working on this now but I don't have any of it up on the site yet. I still have a few things to work out.
You can do zoomed images. If you zoom in manually, and start the web site uploads it will upload your zoomed image. Since you can have multiple instances of GRLevel3 open you can open several instances, zoom to the different levels you want on each and upload your zoomed images for each.
There are some problems with this though and they are not solvable using just GRLevel3 alone as far as I can tell. The four main problems are:
1) Getting the instances of GRLevel3 opened at the zoom level you want. GRLevel3 appears to always open at the base zoom level. I'm new to the SW so there may be something I'm missing that can make it remember the zoom but I don't think there is. It remembers most everything else though when you open it except...
2) You can't get it to start your web publishing automatically on start up. It remembers all the login data but you have to manually start the uploads.
3) The image file names are all going to be the same so if you create different zoom levels and upload the files to the same place you still only end up with one zoom level. The different zoom levels have to uploaded to different locations (ie subdirectories).
4) If you have multiple instances FTP'ing different zoom levels to your server, you may bump into the connection limit set by your host or server, especially if you are already using multiple programs to upload other data.
Four is something you'd have to work out on your own based on the restrictions of the number of simultaneous FTP connections you can have to your server and the other options that might be available to you.
One, two and three can be solved using a nice little program called AutoIt. Basically, AutoIt lets you create a script that can include any keystrokes, mouse movements etc. that you would otherwise have to manually input to get whatever program you want to manipulate setup/started the way you want it. AutoIt can do a lot more than that but for what I need for GRLevel3 that's the best way to explain it. Below is the script that I'm working on to open GRLevel3, zoom in and center the image where I want it, and start the web publishing:
; Start GRLevel 3
; Note the value for WinWaitActive must match the text in the title
; bar of the GRLevel 3 window
WinWaitActive("KTBW Tampa, FL - GRLevel3")
; Open the View menu
; Zoom in one level
; Center the image where I want it
MouseClickDrag("left", 500, 600, 475, 150)
; Open the file menu
; Go down to the Web Publishing selection
; Start the web publishing
As you'll note the script isn't currently changing the upload location so this on it's own isn't going to solve problem three above. I'm working on that part now. I'm in the process of learning AutoIt and the syntax etc. so I have to figure that part out. From what I can tell so far this is well within the capabilities of AutoIt and shouldn't be a problem.