In a word, Yes.
Road: WickWërks rings perform very well with Shimano Di2 on Road applications.
Cyclocross Also Yes.
– Cyclocross History Note: In the past, we heard a couple reports of weird inadvertent shifting when conditions were very bumpy, or rough. Those reports were rare, and ONLY with earlier Di2 versions. With newer models and more refined programming, the later generations are fine. Keep your eyes out, and you’ll likely see Di2 with WickWërks rings in the mud as well as the dry — because many of our customers like that combination.
For Mountain Again Yes. Some of our customers use it with good results. Data is somewhat limited, but we have not heard of any problems.