Hi Espino,
Welcome to Sailpoint Developer’s Community - max size of the attribute is generaly related to the database column size.
It is configurable in Hibernate configuration files and later on “transfered” into the DB schema.
for example here you can see content of LinkExtended.hbm.xml file which contains information about size of Link extended attributes. Same applies to Identity Extended attributes.
Once you change HBM config you also need to recreate DB schema by executing iiq console schema to reflect it into the DB.
Here you can see example of default sized in the DB for spt_identity table
