We're doing a lot of machine learning stuff. I think it's a lot easier for them to write code, play around, and experiment (fluidly) without doing the unfamiliar rigidity of software engineering.

You're spot on with the crappy part of programming. We're using Python, so we have so much less busy-work than other languages.

Maybe I could convince them that growing their software engineering skills will result in a better end-result for them (in terms of professional skill development) and for our sponsor (in terms of a maintainable deliverable), rather than a poorly-documented but fully-functional prototype.