"Many commentators have discussed this passage with a general denial that Paul was to be taken literally."
Many Pentecostals would disagree with those many commentators. I have had that verse quoted at me many times as justification for the Pentecostal belief that babbling in tongues is the Holy Spirit speaking through you in a heavenly language.
The above is a total non sequitur, but you reminded me of my own dark past. Interestingly, you use the term "ecstatic glossolalia". I, for my troubles, have seen plenty of that in my travels.