Just discovered this today! Weeeeeeeee!!!
First off, I cannot imagine trying to tackle doing this one here. But wow, really nice job. I don't think there's ever gonna be a perfect way to do this kind of trading online, especially with Bohnanza which is waaaaay more fast-and-loose, wheely-dealy, IMO than Catan or other games. But it was clear enough once we got the hang of it. Full disclosure: we were also on voice chat.
So, only one 3-player game, but I wanted to say two things:
1. It was never not rough the entire game, having the bean fields drop off my screen to make way for the trading "strip." This is information I need to see - LOL, especially my OWN field, more than the other players. If/when we play again, I will try making my screen smaller to see what I can keep on it. But I think it's worth maybe using a smaller trading strip in some form... or maybe a small substitute bean fields image? Dunno. And if something like is is already there and we missed it... that could be
2. I was invited, which means I had no access to the game or its set-up, so I'm hoping there's a "don't score scoring" option..? I've been playing this game since it came out in 1997, but this was the first time I couldn't induce someone to trade with me because I was "behind"

Actually it was also the first time I could say that and know for 100% that it wasn't true
Thanks again for all the work done getting this here.