Have just received this controller from Amazon, costs vary between GBP14-26 It works and you may see it in my first attempt using it here: https://youtu.be/BF9YnCCN6ZA

Link to Amazon site: https://www.amazon.co.uk/Control-Cam...338360&sr=8-11

It's not perfect, but quite useable for many applications. CX350 has the latest firmware update.