Many (most?) of the middle and high schools in our district has some PLTW curriculum ( biomed, engineering or technology). As far as I can tell, the curriculum is fine. DS and DD used it in middle school and will have at least one PLTW class in high school. The internships are usually for high school students ( sophomore through senior) and with the help of local universities and companies hosting. Only a small number of those kids are over 17 when they start so age shouldn't be an issue.