Thanks a lot for your reply--I really appreciate it. I agree completely that it would be a very valuable experience for me, and I'd like to get experience with interviewing. I was hoping to do it in this one-month interstitial period, but it's been quite busy for me: there's a lot of stuff that has to be done like building the website, recruiting for future cohorts, curriculum design, and so on and so forth. "I didn't look" might be a worse signal than "I turned down an offer from __", but at the moment I don't have much of a choice in which one I get to send.

Well, there is the case of a genetics data-science-ish startup extending me all but a formal offer last summer, and it would be possible for me to get back in touch with them, I suppose, but that was mostly due to the technical strength I demonstrated in an internship and not due to success in the traditional Bay Area tech company interview -> offer pipeline.