Are the remote controllers of DJI Inspire 3 and DJI Inspire 2 interchangeable?

No, the remote controllers for the DJI Inspire 3 and DJI Inspire 2 are not interchangeable.

The DJI Inspire 3 comes with a DJI RC Plus, which improves control experience and delivers longer battery life. It also supports hot-swapping and the new DJI Pilot 2 app to enhance creative efficiency.