A lot of people are doing and have
done what you're doing so you're in good company.
I think it's probably a lot easier to move from
circuit design to system design than vice versa.
Your simulation experience will carry over to systems
from the standpoint of inputting parameters and
then optimizing while being able to judge whether
an output makes sense (too many people don't have
enough gut feel for whether a sim output is reasonable).
My only advice, since you asked for it,
is to document all your best experience, including
any leadership roles, and then emphasize anything
that can apply to systems / controls.
luck to you. Let us all know how you made out.