Are the DualSun SPRING panels compatible with the RENUSOL - VS+ Double threaded screw mounting system?

Yes, and this compatibility has been attested to by an independent Control Office which has issued a New Technical Survey (NTS) to confirm this. 

Some DualSun panels are therefore compatible with the RENUSOL - VS+ Double threaded screw system:  

• Types of roofing: pitched roof
• Certification: DualSun Flash panels are integrated into the NTS L.21.60367
• Modes: Landscape and Portrait 

You can also consult the documents available on the manufacturer's website

For more details about the installation of DualSun panels on the roof: What mounting system can be used to install DualSun SPRING panels on roofs ?

To see the compatibility of DualSun SPRING and FLASH panels with the installation systems: Compatibility table