Looking for help to set up RAID6+Dual SSD cache

I have 12 4TB SMR drives that I wish to set up with RAID6, and use two SSDs as a cache for the array. I know how to set up RAID6 in Win 10, but I am not sure at all how I would connect an SSD cache to it.

All my drives are external, using USB 3. They are connected to twelve ports, which share 6 individual controllers.

I read somewhere that setting up the SSDs in RAID1 is a good idea, for better reliability.

I have a few questions:

  1. How do I set up the SSD cache in connection with the RAID6 array?
  2. Does using an SSD cache in this setup add additional corruption risk compared to just using the HDDs in RAID6 without SSD cache?
  3. Pros and cons?