Oh, I gotcha...I believe this could work. . .but....what if, let us say, somebody has multiple accounts with OSRS gold elevated levels and a single pure. They have two computers also log the pure one and among the top ones on the opposite. They can now give free exp into the pristine, log off the first high level, get onto the next, and repeat.Even if there was a exp cap, this could still get extremely mistreated... You have a major point there. I will think of a way to stop this type of abuse.
Should you read the RuneScape Manual, JaGex states,"You can earn a maximum of 30,000 experience in any 24-hour period by assisting people". I believe that's enough to prevent people from giving free XP to their pures. Plus ? Is such a small amount of XP it likely would not even be worth doing. They'd need to continue to keep their main logged in and in a 20 square radius of each other.
When they did this they would be breaking the multiple logging in principle, and two individuals using the exact same IP address can not log to the same world so it would be quite hard to do exactly what you are saying. Notice how I said different computers. I mean, would not it be cool, riding a horse around Old school runescape buy gold instead of playing some crap toy horse (can be quite entertaining sometimes) I'm still in the first phases of the thought and theres more to come. So far I have just thought of this carriage, how this could work and how to get you.