Correct me if I'm wrong (SCH is nowhere near my main, and I forgot to test last night), but putting the fairy in Steady keeps her from auto-casting until you give her a command (at which point she starts auto-casting), right? If that's the case, rather than (or in addition to) using Heel/Stay/Steady to cancel an auto-Embrace before what you want to cast, couldn't you macro everything to put her back in Steady after the cast?

So adapt all your Embrace (etc.) macros to:

/whatever else you've already got before the pet skill
/pac "Embrace" <t> <wait.3>
/pac "Steady"

Since Embrace is always 3s, she won't have time to start autopilot again.