If someone has had a career as an interim executive & they decide to return to permanent work, that does not mean that they;
a) Have moved around a lot.
b) Can’t stick at anything.
c) Will get bored and move on.
What it actually means is that you have the opportunity to shortlist an ‘out of the box’ professional who has vastly more perspective than anyone could possibly have gained in a purely permanent career. Not just perspective though, but breadth, clarity and insight that tracks back to recognisable, generic patterns of behaviour (yes, I am afraid your industry sector isn’t unique) as well as forward & therefore with the wisdom & insight to know what to do about it.
It is lazy, ignorant recruitment to dismiss these people as transients. It is their job to transition between industry sectors, measure commonalities & sweep away dogmatic & fixed mindsets that cause bottlenecks. If they’re coming back to permanent work, then you have yourself a treasure.
Because of IR35, some of them are. It is sensible to listen to what they can tell you. This isn’t an easy game to endure in, so these people know of what they speak.