I finally took the plunge, watching the Chinese supplied Youtube Video was quite helpful really ( thank God for the subtitles ) I was a bit nervous stripping down the original RC unit ( I have recently purchased the Smart Controller, but didn’t want to risk damaging that ) took about an hour with little gaps inbetween to study the video or rewind a few times to check where the left over screws came from etc, the hardest part I thought was getting the original antenna sticks out of their mountings, the method the Chinese guy demostrated looked much too risky for damge through slipping etc, I opted for a small flathead screwdiver to wedge them out.
By the time I finished it almost dark, but I did a quick test flight in the freezing 1deg C outside temp & it worked fine, so no controller damage, I haven’t done a proper range test yet, but I have my smart controller to compare against, luckily they are both paired to the Mavic 2 Pro so really easy to use without having to pair one or unpare one depending on what I need.!
Specs : Product model: DUO-2458SSB
Dual-Band, Work with 2.4G and 5.8G
Working Frequency Band: 2400-24835 GHz / 5.725-5.850GHz
Working Voltage: 6-9V
Antenna Gain: 2.4G>13 dBi±1 / 5.8G>15dBi±1
Receive Gain: 10 dB±1
Transmit Gain: 15 dB±1
Input power range: 10-20 dBm ( can be used with FCC modded RC )