I worked for a few airlines in the past both as a gate agent in College and as a pilot a few years later. Its just plain awful how little standardization there is. You could get a nice helpful agent/manager and they will go out of their way to help you.
Most are so pissed and bitter at the airlines though they dont care to help at all. This is why one tells you yes one day and another agent basically tells you to get bent the next. This isnt just a problem for customers its a problem for pilots also.
It has gotten to be such a hassle to jump seat on an airline its not even worth it, I cant tell you how many flights my self and other crewmembers have missed because the agent dosent know how to properly work the computer. Some are on such a power trip they will
not even allow you to ask the Captain for a ride, even though the Captain is the final authority on who rides in the jumpseat. Even if you did manage to get your jet on board i still wouldnt recommend sending it, as a previous agent/baggage handler I know
how poor those bags and boxes are handled. Fragile stickers dont help either most idiots will go out of their way to be rougher on those.