Secondary CANBUS systems are slower than primary CAN buses in both Subaru and most modern vehicles. Primary buses (usually 500 kbps to 1 Mbps) handle safety-critical data like engine and ABS, while secondary or “comfort” buses (125 kbps, introduced in 90’s) handle less critical, slow-paced tasks. This puts CANBUS based OEM DCCD Controller (or any substitute with CANBUS) in huge disadvantage to Spiider DCCD Controller that directly reads conditions and responds to control of DCCD electro-mechanical system. . It’s just simple math and physics and and 15 years of results on podiums to prove it 
