dual boot Mavericks & Yosemite

Hi

I have been annoyed too many times by little issues in Yosemite. Installed a second SSD and installed Mavericks. Assume Apple will eventually fix the issues so plan to go back to Yosemite.
I have Devonthink Pro Office installed, up and running on Yosemite. It would be very convenient if I can “attach” to that environment when booted from Mavericks. My Documents folder is soft linked from the one in Yosemite to the one in Mavericks. Databases can already be opened.
Installed DTPO (same latest version) on Mavericks, but get questions on the license. What is needed to use the configurations, settings, etc as available on Yosemite while booted from Mavericks?
To set stuff up in this way makes it rather easy when switching back to Yosemite. Or perhaps I still have to boot from Y due to some other application demanding this…

In your dual boot system you are using two user accounts. As your registration is managed in each user account, you need to register it in both of them.