There is a recent interview with the developers at NG.DEV, in which they address the Retro VGS. They make some interesting points. Unfortunately, due to piracy, NG.DEV won't be doing any additional Dreamcast ports. The question about Retro VGS is below:

Archaïc : The new product you’re talking is RetroVGS console, is’nt it? RetroVGS announced adapting Gunlord on their console. Why this partnership?
Timm : No. I’m speaking about something different, an arcade hardware. The RetroVGS is not really an existing product right now. The RetroVGS is more an idea for now. We choose the RetroVGS as a potential port platform for Gunlord because we like cartridges and the way the crowd funding campaign is setup there is no risk for us in waisting time and money. If we port to say Wii-U we don’t know if only 2.000 people buy it or 20.000. It would be risky at the low sales price of digital downloads. RetroVGS will also offer better service to developers than the big platform holders.