Can I upgrade to the UDK+?
Edited
Absolutely, you can upgrade to the UDK+ at anytime and pay only the pro-rated amount.
As a reminder, the Ultimate Tier subscription includes the UDK+ as part of it and is a great option for those wanting the full package of draft prep and in-season tools.
Navigate to your account page to upgrade your UDK or sign up for an Ultimate Subscription.