Undo Racking / convert from keg into smallpack

Hi there,
I am needing help or advice on how to undo racking (3rd party contract brewed).
The batch was to be split between 50% keg and 50% can - however it was mistakenly racked 50% to keg twice.
I cannot use the undo function as it states that some of the kegs have already been invoiced, but this is only correct for the initial half batch and I also receive this error message:
“This action’s parent vessel is not empty or is filled with a different parent action.”

Is there a way to undo the racking of kegs and covert into smallpack (in a similar way to disassembling multipacks)?

If you can’t undo it, maybe:

there’s a related feature request that (if implemented) would allow a workaround for this.