Hello Bartira,
The qRFC entries you found on SMQ2 are meant to perform the delivery split, thus creating a new delivery document. The error messages you get seem to be caused by missing customizing.
I suggest you go to ECC IMG (SPRO), and look for the following node:
Logistics Execution> Shipping> Deliveries> Subsequent Delivery Split
In this IMG activity you need to define a delivery split profile (you can choose a standard one, I suggest trying 0003), and then assign it to the delivery type (in this case your custom ZVMI).
Hope this helps.
Regards.