I got my Corvus shell deflector a few weeks back, shipping was very fast from Austria, and Florian (the guy who runs the place) was excellent to do business with. He even refunded my 20% VAT tax from the order, as I'm outside of the US. This was something I had no idea about, he could have easily kept the money, but on his own he refunded it. Very much a class act.
The shell deflector itself is a very elegant design. There's the triangular aluminum wedge, and then a separate aluminum rectangle with hooks that fits over the ejection port. You just slide it in, and then tighten the two set screws in the wedge to get the hooks to engage with the ejection port.
Here's an excellent write up about it with pics and video from a German gear blog:
http://spartanat.com/2016/11/review-corvus-defensio-huelsenabweiser/
As for the trigger, I talked to him and he's hoping to have the trigger packs ready sometime 2017, as well as hopefully some accessories for the A3 M1.