Hi,
I don't know what the repercussions are when you go over the limit in your licence but I know if you are using the base license with the new software version 6.0.196.0 you can use some of the features of the WPlus license:
WPlus License Features Included in Base License
All features included in a Wireless LAN Controller WPlus license are now included in the base license; this change is introduced in release 6.0.196.0. There are no changes to WCS BASE and PLUS licensing.
These WPlus license features are included in the base license:
•Office Extend AP
•Enterprise Mesh
•CAPWAP Data Encryption
Read the release notes in this link:
http://www.cisco.com/en/US/docs/wireless/controller/release/notes/crn6_0_196.html#wp616502