What is a key limitation of using Customer Managed Keys to encrypt data in AWS?

The choice indicating that the plaintext data must be 4 kilobytes or less is not a key limitation when it comes to the use of Customer Managed Keys for encrypting data in AWS. In fact, AWS allows for the encryption of larger data sizes, which means this assertion does not accurately represent a limitation.

A more accurate understanding of Customer Managed Keys is rooted in the fact that while they provide significant control over encryption, they are not universally applicable across all AWS services. For instance, certain AWS services may not support the use of Customer Managed Keys for encryption, therefore limiting their utility in those contexts.

Additionally, encryption is commonly supported across multiple data types and accessible for various storage solutions, and the limitations related to specific data sizes are generally not an issue within AWS's services. Thus, the idea that certain data types can be encrypted doesn’t convey the nuanced understanding of the limitations associated with Customer Managed Keys.

Therefore, the focus should be on the inherent limitations related to the capability of Customer Managed Keys in terms of consistent application across the diverse array of AWS services, rather than the size of the plaintext data.