I am a big fan of PBL having witnessed its successful applications first-hand in arts integration programs serving elementary/middle school students; in the Expeditionary Learning School (grades PreK-8) I am currently doing a project with; and of course with the Reggio Emilia approach for our youngest learners. I came across this great podcast in which 10 educational leaders from around the country are speaking on the benefits of project-based learning and the challenges to offering more high quality PBL at scale:
https://www.gettingsmart.com/2017/02/getting-smart-podcast-10-leaders-on-high-quality-pbl-doing-it-well-at-scale/