I've had a quick look for an article I found some time back about the pros and cons of link pipes between exhausts on twin cylinder bikes but it's escaping me for now. The upshot of what I'd read was that a crossover pipe improves the lower end power, and separate pipes can give you more at the top end, but you lose at the lower & mid range that most of your riding uses.
However, the Guzziology bible suggests that larger volume crossovers can increase flow and power where they're basically empty boxes, but reduce mid range. Where there's any kind of silencing in them as there usually is to meet restrictions without making even bigger silencers, then you're not getting that effect.
What you're possibly better thinking about is keeping some form of crossover, but not a big volume in itself.