At an old firm we did this:
If company wanted the training the tuition and travel were paid, you got paid and earned vacation time whilst training. For example high voltage course or auditor or some such
If you wanted training that was useful to company in company discretion but not required by company you would get reimbursed the tuition and travel costs but no pay, no vacation earned however no paid vacation time was deducted whilst you were on the course. For example a license upgrade …
It was a good program and the guys liked it.