Do I need to download only upgrade for Komplete?

vagabond09

I currently own Komplete 14 standard. A friend of mine is giving up music, so he is willing to transfer his Komplete 15 Ultimate license to me for a pretty good deal.

What I'm wondering is his purchase of Komplete 15 Ultimate is just the full version and not the upgrade for Standard version. If this is the case, can I still install and upgrade from this without any issues?

I have a lot of a third party plugins that I've also purchased, so I was wondering if I would have to reinstall everything.

Thanks in advanced.