Edit Date is not correct after Undoing and a catalog private write happened before it.

I am observing this 

1. Set up a smart collection "Is Edited Today"
2. Change Develop Settings or change metadata for 1 image (E.g Reset Settings)
3. I purposefully wait 10 seconds

4. On demand with my own plugin I find the image edit at step 2 and my code auto writes to the image a custom metadata via catalog:withPrivateWriteAccessDo()
So the image IS touched by the plug-in but privately, not part of the undo stack.

5. Undo

Result: The photo no longer appears as Edited Today smart collection BUT at step 3 it was touched by the plug-in, privately. 

Here are the detailed steps:

1. Photo before Reset

lastEditTime = 790266710.87918

2. I reset it

3. I update the custom metadata

lastEditTime = 790702916.12329

4. I undo

lastEditTime = 790266710.87918
 
IMHO
LrC should be smarter than this and keep the lastEditTime IF it is more recent than the lastEditTime of step that was undone.
There might have been changes not part of the Udno stack, but they still happened.