Seeing how PotD has a time limit, I really see it being counter productive to the completion of the duty to have training dummies inside. Also a person new to a job will likely be learning 2 new actions every single floor of the run, and you can't train them on how to use skills they don't have at the start of the run, nor would it be sensible to have a dummy on every single floor of PotD 1-50. The way it works now is hopefully people read tooltips as they learn skills, and move them into a sensible spot on their hotbars. Dummies should be used in between PotD runs if people truly care to adequately familiarize themselves with skills, assuming they don't catch on quickly during the run.