Addressing your immediate issue of getting a macro restored and ignoring the broader issues you brought up which are for @peternlewis to address, my method is like yours but I think simpler. Let’s say Today you want to restore a macro from Yesterday.
In the KM Editor, I’d use File > Revert Macros > Yesterday to restore where I was Yesterday. I’d export the macro in question, use File > Revert Macros > Today to get back to where I was earlier Today, then go to the Finder to double-click on the exported macro to get back the macro in question. Of course, you’d then need to do any cleanup of the copies of that macro since you’d have Today and Yesterday copies.