The MindConnect LIB license is linked to the MindAccess Developer account. Therefore, a developer using the LIB to create a custom agent based on the LIB has to maintain an active MindAccess Developer account as long as its end customers use the agent with the implemented LIB.
If the MindAccess Developer account is no longer active, the developer has to make sure that its end customers do no longer use the agent that is based on the LIB. However, this does not necessarily require deleting the compiled LIB from all devices. It would suffice, if the developer has created a contractual relation with its end customers based on which the developer can demand that the usage of the LIB is discontinued by end customers. Such contractual restrictions towards end customers are required by the LIB license anyway.