Why not just take a couple of seconds during your brief and mention at what stage, providing all goes to plan, control will be passed from right to left. Then providing nothing out of the ordinary comes along all concerned know whats going on by Capt Drag
Excellent, and since it is now a briefed item, the First Officer can now release control to the CA, much more civilized than " my airplane" or "I have control".
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Although there is no limitation for idle reverse, it is a good operating practice to get them stowed to prevent fan erosion.