In my opinion, Rodrygo should stay at Real Madrid, he should be more patient, the league hasn't started yet and it seems to me that the new coach is still experimenting with the squad to have a definitive formation and players who will always be the ones to start the game. He probably still wants to see what the best position is for Rodrygo and Viciniu Jr. because both of them haven't been able to score goals consistently.
The best thing for Rodrygo right now is to leave Madrid. He doesn't need Sherlock Holmes to tell him that he's not in the coach's plans for him to see that. Even if he was in the coach's plans, he would always be the second fiddle in that team. If he wants to stay, then he has to know that he will fight for his place and prove to the coach that he deserves to be the starter ahead of anybody that's competing with him, and to be honest, Rodrygo isn't that good. No matter how hardworking a player is, he can't give more than what he has in quality.
Rodrygo is played out of position, and that will always limit him. If he goes to a team like Arsenal, where he would play as a LW he might perform better. Advising him to remain in Madrid won't help him. People make names for themselves in different teams. If Odeegard had stayed in Madrid, he would not have been the player he is today.