@Starry I'm glad that any input I had was helpful in helping you understand your ISFP. Even more surprising that it/I/my comments had an impact. That makes me happy to hear.
I've known a lot of ENFP's. And each had their intellectual side, where they wanted to discuss deeper matters. But a lot of them showed more of a playful side. Especially the ones who I would consider e7's. And most of them leaned more towards the spiritual/hippy side.
The two in particular that I thought might be e5's had less of that religious/spiritual side and more of the debating side to them. But the more I think about it, the more I think they may be more 4w5. I'm not as familiar with enneagram as I am mbti.
Oh, as far as ISFP's and intellectually stimulating conversation goes: we do enjoy it. Or at least I do. But it depends on the manner in which information is being presented and also who is involved in the conversation. You'll never catch me in the middle of a group discussion. And especially if some of the speakers and opinions are of mean spirit. In more personable groups, I'm willing to discuss ideas to greater lengths. Or at least hear them out.