Being under the influence of any level of AM will supercharge your Merit WS and activate it's Aeonic WS property. It will also count as supercharged FOR the WS that is activating the AM.
EDIT: Made a small video with something fancy as SCH/RDM
Wish it wasn't so unsteady and hard to pull off. Only managed to do it like 2 in 20 tries. However I don't think instacast triggered during the attempt I captured.