Perhaps à good change to CU would be to remove the channeling.
Since the optimal usage is to not channel it, beside niche situation, and that the channeling part confuses new AST, simply removing it would solve the issue.
Possibly, to prevent weird animation and make the whole noc effect lasting 5s more clear, they could make the bubble visual stay for 3~5s.

Additionally, adding an effect depending on the stance could further help solve the issue with Nov vs Diu.

Diu could have a better potency (possibly back to 150) and noc could have a shorter cd. Making it more akin to SS.