You could say that, annother possibility is: Vielen Dank nochmal, dass Sie sich heute Zeit für mich genommen haben. <- sounds much better and seems not like a phrase. You said you where in a telephone conference? A possibility in this case is: Vielen Dank nochmal für das Gespräch heute! That discripes that are not only thankful for his time, but also for his or her's time. Hope I can help you.

No, it doesn't make sense. There's an increasing use of empty "Vielen Dank" phrases, e.g. "Vielen Dank, dass sie mit der Deutschen Bahn gefahren sind", which was just not a thing twenty years ago, but thanking for your time hasn't made it into German (yet, who knows).