True, but this in design would be a step in the direction you wanted.
And like BeachEMT said, a good amount of WA magazine hold 50 rounds. Which is why i too always wondered why kwa never did 50 as well. Maybe the physical size of the magazines are different as ive never done a side by side with the lm4.
Haha, we all wish we could get one. The uploader posted simply "this is a private mod". It might be a longshot to try and contact him in order to understand what all he modified... Even that is wishful thinking. But, it IS possible. at least there is that hope.