Hi,
As of my knowledge, there is no option in standard to move the consignment stock from one vendor to another vendor. Neither it doesnt have any business logic since the consignment stock is the vendor stock procured against a legal document and lying in company warehouse.
You may reverse the consignment stock with return delivery or return PO to vendor A (not physically) and create a consignment PO for the material with vendor B and receive the stock with 101 K for vendor B.
You cant use 411 K and reversal with 412 K to another vendor, since it will create liability on the first vendor. Same in case of 551K and 561K combination.
Regards,
AKPT