How to spin nonconventional internship?

Some background--during the school year, I've been interning at a small private equity firm with only a few portfolio companies. The company's structure is very flat, which is awesome and entails a lot of responsibility for the junior people. In addition to performing the usual excel powerlifting, I also work on the operational side, i.e. entering new markets with product X, taking care of exchange risk, negotiating with suppliers, etc... So far, it's been a very unique experience--for example, one of my opco's was experiencing margin compression as its cost of shipping spiked (its customer base was located on a relatively self-sufficient island). I had to create a new model to allocate shipping price based on product type and volume, re-ran the valuation with new price/margin/demand assumptions, and negotiated new rates with the freight operator.

While I learned a shitload more during this job than my summer ibanking internship, I'm curious as to its applicability to a more conventional PE role. I'm currently an undergraduate in my third year and hoping to interview with a few PE shops for full time. On my resume, should I list my positions in the portfolio companies separately or under the PE shop (my actual roles/experiences in the opco's varied greatly)? I've done it both ways, and interviewers (read: HR) has been thoroughly confused. And secondly, do PE analysts/associates ever get involved in the operational side of portfolio companies? I'd assume this is more common in MM or DD than megafund?