Meh, renforcing Selene identity as the global team damage enhancer would be better. SCH don't really need more heal, being the off-healer isn't his problem and it shouldn't aim for easier solo healing by just more numbers. That's how WHM does things, not SCH.

Maybe, making the silence into a 15sec duration/120sec cooldown vulnerability up (5% ? 10% seem a bit high with chain stratagem and fey wind up at the same time) could very well do the trick and make the SCH reliable 2 minute CD burst support. Also dissipation as a skill the switch between fairy seems the better way to rework the skill, but simply swiftcasting another should be impossible in battle if one of them is already out.