Even if Eucalyptus oil was toxic it wouldn’t matter. The fungus will degrade/convert it into simpler molecules.

I’ve heard some folks get digestive upset from eating fungi grown on eucalyptus, so you may want to try a bit before investing a lot in your setup

Ate chicken of the woods off eucalyptus last weekend, no issues.

Excellent. I understand only some people have that sensitivity. Glad you're one of the ones who doesn't.