Here what I did
- Make custom WF for C_PaySelection table
- Use setIsApproved(true) instead of setProcessed(true) in the M class' completeIt method.
IsApproved still will be updated by Create Payment process, meanwhile IsApproved will be used in Read Only Logic for another field.
I don't know if this is a good workaround, but at least it works.
If you think something is missing here, feel free to share it with me.
Thank you.
Regards,
Iqbal