Key Attribute Data - Multi Line issue

Hi 

We have a customer who is starting to use Key Attribute Data and they have an issue with the multi line field where it only allows upto 255 characters (even though the following link says it's 500 The Key Attribute Tables - Hints, Tips and Tricks - Downloads - Sage CRM Community

Ideally it would be great to have it work like a normal 'multi line' field which is an nVarChar(MAX) and can handle tonnes of characters. Is there anyway to change this in CRM?