If you need a trailer, just go buy a Convertible car... J/K - Kinda
The bikes I have ridden with trailers have really great brakes and are much longer than the XS650. Stability is an issue to consider with these short wheelbase bikes and adding any kind of weight that will want to "push" the bike around.
True, even in tractor-trailers, the longer road tractors are noticeably easier to drive than shorter tractors pulling the same trailers.