before and after for the last adjustment

What problem do you see this solving?

Before and after is not very useful since quite often a bunch of global corrections are made to an image and comparing the original to current is often not useful. If one could compare the last edit or last few edits it would be helpful to see if those last edits are desirable. The first few edits are usually bigger moves and the last few or last one are finer and harder to tell if desirable. This is where an option to toggle the last adit or a history panel would be welcome.