Thank you for your question, Steve.  This combination of a planting medium may work, but some drawbacks include the fact that peat moss is difficult to re-wet once it dries out, so doesn't make water and nutrients available to the roots.  There is also the concern that the pH of the mixture may promote scab.  Perlite adds no nutrients, but does retain moisture.  I suggest that you read the following Extension article, and get a "soil" test before planting:  https://extension.oregonstate.edu/gardening/techniques/grow-your-own-potatoes
Good luck!