Has anyone tried to create a customization to reverse the GL impact of Credit Memo by creating a dummy Invoice? I guess this has to be scripted but how difficult it is?

just to understand, why do you want to reverse the GL impact? a JE can be used to cancel it

is CM a source for revenue arrangement? If so merging must be happening more than once.

Users are too lazy to manually create a dummy invoice (this is a very particular business transaction where CMs usually need to be reversed). A JE does not affect the quantity on hand though. That’s why we decided to use dummy invoice. And no revenue arrangement, just direct posting of revenue. If we use GL plugin, that would keep the CM open though, wouldn’t change the status.

so help me to understand…. “users are too lazy to manually create a dummy invoice”, but they will create credit memo and invoice?

They don't want to create manually the dummy invoice anymore and manually apply it. Going forward if this works, they just need to create a CM, and then by clicking a button a dummy invoice is automatically created and applied.

yes, Create record will take you to the open record. I am thinking that perhaps you can create line on that record with the WF out of the box? not sure. About to dive into a similar request - to create a record and populate the lines based on a saved search results

in your case it would be more interesting to make a simple script that creates the dummy invoice