That is not correct. The regulations state that the aircraft must be ‘within Visual Line of Sight’. It does not say you cannot look at the controller screen. It should be obvious you have to do this to ensure, among many things, you are aware of...
Although I can’t answer your question directly, I can tell you that this site may not be the best place to request that type of info. You will often get lectures on VLOS even though you are a grown and fully responsible adult. I say this...
I though the RC Pro for the Mav 3 had unscrewable SMA attached antennas. The first smart controller did, I think. If the new RC pro doesn't have replaceable antennas, I for one wouldn't try modding it with the Alientech DUO either.
I got the Mod...