How long the scout can sit on the resource seems to have toned down somewhat with v1.21f as compared to other patches. But it still works. Also, you could sign a ROP and never worry about moving. How long you can have your scout sitting on the iron hasn't been fully figured out, but here are some notes I made on another thread:
I think this depends on some things:
1. Your reputation. The better your reputation, the less likely they are to make you move. As the game would progress, and I accidently left my scout inside territory, when doing the 0-turn war (thus bascially doing a ROP abuse since my scout was in their territory), this would hurt my rep and my scout would be asked to move alot more often.
2. Your power ranking. The more power you have, the harder/easier it is to leave the scout there?
3. If the tile is immediately adjacent to one of their city center squares, the more often you get kicked out. If you are in their borders, but not right next to the city, you get to stay longer.
4. When they give you the ultimatum "or else", go ahead and leave, but on the very next turn move back on the iron.
5. If any 'normal' military unit (warrior, horseman, etc.) happens to move inside their territory, you will get booted out. Sometimes they don't even like your workers in their territory, either, so watch them workers. The scout is considered a 'non-military unit' so it's not viewed as much of a threat as other units.
6. If I keep moving units around their territory, I will frequently be kicked out, but if the scout (non-military unit) just stands still, he can stay there for long periods of time.
