Well I don't have an X79 to do proper testing with, all I can do here is change the PCH controller ID to mimic X79.
With this configuration using RSTe 3.0 driver or RSTe 3.5 driver trim for RAID0 does not work, only trim for non-array SSD's. Whether this means the driver itself does not support RAID0 trim I do not know but due to not having a true X79 the results are at best dubious. I wonder why Intel included the option to identify a RAID controller on 6 series PCH as a Patsburg X79 RAID controller.
I do have a series 5 board though, so will try to make some time over the weekend to test it.