I'm aware that Lumagen has been through this before with Radiance XD/XE together with the HD621, in or about 2009. At that time M lent them a HD621 for testing for 8-9 months. They basically told me they would need to repeat that process for the new 2021, but need another HD621 in their lab again for troubleshooting. I didn't feel like being the guinea pig. Path of least resistance was eliminating the Radiance. Too bad since I still feel it's a solid product.