I agree that the training could well be optional, and so done at the convenience of the tech, and done to better the techs own knowledge, how ever I think the line is; "when it MUST be done, and when it MUST be done at a certain time", then it is no longer an option, and no longer at the convenience of the tech, so it must be paid for according to federal wage and hour rules, which only allow a 40 hour week at regular pay, and require 1.5x pay after 40 hours in a week. When the tech has the option of not doing the training, and no harm or foul become from it, (just possibly not as much a raise or some other "atta-boy") then there is no reason to expect the company to pay for that time.
A lot of the better companies do have a tuition reimbursement to pay for your college level courses, especially if they are related to your job, and I know a few that even do provide a stipend (not hourly pay though) for students of certain courses.