The Spanish thing is quite funny, they have a LOT of names.
You had a very good explanation that it only becomes an issue from a system point of view if it gets included as part of your first or last name, and primarily the last name.
Which is technically correct. Once you receive your eCOPR as an inland applicant you're considered landed and have access to all services. The ability to re-enter the country in a hurry isn't really their problem since you're an inland applicant. Having said this - the delays on this process...