I don’t see any Specular Reverb modes that you could not emulate in the H9. For the shimmer mode, I would use … the Shimmer algorithm. There are other ways to do this in an H9 Max, but this one is the most straightforward. Here’s an explanation of the Shimmer algorithm by parameter:
https://www.eventideaudio.com/products/algorithms/shimmer
I found an earlier thread with some Shimmer parameter detail from Eventide, and myself. I put together a little demo program that might help you along. If you get stuck on any specific points, reply back.
https://www.eventideaudio.com/community/forum/stompboxes/h9-shimmer-pitch-decay-etc
