"We've all got a lot on our plates," is frank but pleasant enough. "But I think ... you know, no one outside here is doing studies on rifters, really, so I think it makes sense to keep it in mind when we're considering our focus."

(Well, the Venatori might be involuntarily experimenting on rifters when they get a chance, but that certainly doesn't count for these purposes.)

"Keep me posted, if you end up having follow-up ideas, and I'll reach out if I end up with more questions. But I appreciate your time."