So, I called Z-Spar and spoke with one of their chemists. He said that once the varnish has fully cured (one week after top coat), it "seals itself" and doesn't outgas further. At this point, short of eating it, it's harmless. If anyone out there has any controverting or corroborating information, I'd love to hear it. Otherwise, I guess I'll take this guy's word for it. Thanks again.
Cheers,
Forrest