Interesting. I was hoping to do exactly this using the SBE-1 to re-create the SBus stream from the Cortex outputs. I will have to give it a try and confirm.
FYI, the original iGyro (not the new less expansive one) DOES have an SBus output (in fact two "Dig out" ports have the SBus stream with the Gyro corrections included).
I had an issue with one of my iGyros not putting out this stream correctly and learned from the PB guys that some of the early iGyros needed an update back at the factory to update so the serial output would work. As usual this info is available on the PB forum, and they are happy to have the unit back to correct it. They seem to be a really first-class company from how they support their customers.
I think the reason I have an interest in this topic overlaps with some of the others here .. to marry a good gyro with the Robbe 2018. I think the only way to do this properly at this point is to use the original iGyro, then feed both of its digital outs to the PSS2018. The only slight issue here is that if you use two RXs, the iGyro will select the active receiver and put that signal out to both Dig out ports, and will not pass along the signal quality info to the PSS. So if you are accustomed to having the RX signal performance in the 2018 log file on the memory card, that will be lost.
I am sure the PB guys would just suggest using a Royal SRS with all the functions (and more) of the iGyro and PSS2018 already included :-)
Dave