The collector box has scavenging built-into it, it's actually quite efficient; just compare it to a Cobra 4-into-4 for sound and HP. Sure, your exhaust could physically be reworked to eliminate the collector box, but you're looking-at less peak HP, more noise, and the cost of doing it. That sounds like a crummy trade-off for what is supposed to be a performance bike, from its stock configuration. Use of the stock megaphones scabbed-into the system with your modded swingarm probably is possible with enough time and skills, but replacement with something-else is probably a more cost-effective path.
I'm sure you could fab some-sort of a crude manifold tying the four headers into a crosswise-tube, and then a single tube at either end to a pair of literbike (or bigger) dual exhaust canisters. It won't work as-well as-stock, it won't look stock, but it would allow your braced swingarm.
Was this a custom Dutch fabrication? I would expect that retaining the stock exhaust would be a priority in its design, or a bold italic warning that you would need to replace the stock exhaust, to fit the modified swingarm, prior to purchase to fully-inform the prospective purchaser. Kerker mentions in their 4/1 VMax system about having to remove one centerstand bracket, and the need to at-least bend the other out of the way, if-not also remove it.
Sounds like you should just live with the system as it is and keep your euros in your wallet.
