If you need the full functionality of GAP4 Monitor GAP, you will need to purchase a GAP4 Monitor License..
In order to use a GAP3 Monitor License with GAP4 you will need to install GAP3 and License with GAP3.
If you try to monitor with GAP4, it will check if there is a GAP4 or GAP3 license. If either one exists, monitoring will work (at the appropriate level of capability).
GAP4 honors previously authorized GAP3 licenses for monitoring and editing. The GAP3 licenses only authorize GAP3 functionality. For Monitor GAP, GAP3 license means
No OLC support
No monitoring of curve tables