No. It wouldn't make any sense to step back in history while using the tool, since the tool doesn't make multiple history states.
You can use Ctrl-Z to undo/redo the very most recent change (e.g., movement of a corner).
It wouldn't make sense, unless the PS developers decided it was important to allow for such intuitive UX.
Feature request! Add history states to tools... pretty obvious ya?
Yes, there is an occasion when in Free Transform, Ctl+Alt+Z (Cmd+Opt+Z) does perform a useful task. For example, during Step-&-Repeat when you when you want to undo steps sequentially. These are the Mac steps:
The Step-&-Repeat method: To replicate the effect shown above – creating equally spaced duplicate images:
1. Open a new file of appropriate size to hold the finished Image. (File > New)
2. Choose the master image file and select the object. In the example above, the Magic Wand was used to select the area surrounding the object and then Select > Inverse to create marching ants around the object.
3. Choose the Move tool. Click and drag the object onto the new file and in position it at the left. It will become the start of the row.
4. Select the object. Once again, the Magic Wand was used to select the area surrounding the object and then Select > Inverse to create marching ants around the object.
5. Hold down Cmd+Opt+Shift and choose Edit > Free Transform. Be sure to release the mouse before releasing the keyboard keys.
6. Hold down the Shift key for alignment and drag the framed image to the right. Do not use the center mark in the image when dragging. When dragging you may completely separate this image from the one at the left, or allow it to overlap the one at the left as shown above. Then key Return or click on the Commit mark. The second image wlll display marching ants.
7. Hold down Cmd+Opt+Shift and strike the T key repeatedly. Each time you do, another duplicate will appear, following the spacing you designated.
Before deselecting the marching ants around the final image, if you choose Ctl+Alt+Z (Cmd+Opt+Z), you can delete each step in sequence starting with the last one.
That's a little tangential, but very nice to know!
While Step-&-Repeat is applied more often in Illustrator, I think you will agree that its value in Photoshop is undeniable. And I believe you will agree that any technique that requires multiple steps would benefit from a sequential undue function. It truly is, as you put it, "very nice to know". Nitpicker that I am, and screw up that I am, I appreciate this undo and am rushing to its defense. It uses the shortcut the questioner inquired about, and performs a useful function. Give it a break and don't tag it "a little tangential". Wadddyasay?
Yes, it is very helpful to know! I wonder, could the same thing be achieved with an 'action'? It's tangential, beccause it is not addressing the intent of the original post, instead it opens a new subject which regards automation- it is its own topic, thus the tangent.
To be honest, I am surprised that Noel Carboni would actually say that it doesn't make any sense to have a multi-step undo in the transform mode...