The controller of the modified DJI Smart Controller/RC PRO can be equipped with an external ALIENTECH antenna.
ALIENTECH PRO 5.8G Booster Range Extender for DJI Smart Controller
Amazon.com: SYMIK Neck Strap Aluminum Bracket and Neck Strap (Lanyard) Combo for DJI Smart Controller; Works with DJI Mavic Air 2, DJI Mini 2, Mavic 2 Pro/Zoom Drone with Smart Controller : Electronics
DJI RC Smart Controller
DJI Smart Controller Review: Who is it for? - DJI Guides
Best Buy: Smart Controller for DJI Mavic 2 Mavic Air 2 and DJI Air 2S CP.MA.00000080.01
DJI Smart Controller Review | Trusted Reviews
DJI RC Pro Smart Controller (CP.MA.00000406.01) - Moment
DJI Smart Controller for Mavic2 Pro - MotioNew
DJI Smart Controller - DJI
DJI Smart Controller - Unboxing and Review - YouTube
DJI Smart Controller Review: Who is it for? - DJI Guides