Character limit for "Source expression" in Data Exchange/Integration

Summary:

We have an requirement of deriving target values from the source values before the Data Load Mapping is processed in Data Integration. the character limit in the "Edit Source Expression" option in Data Integration we have right now is not sufficient for us to configure all the values and the achieve the requirement. is it possible to increase the limit on request?

I understand this can be achieved in the Data load mapping(which is the current process) but this is needed right before the mapping is processed to reduce the work needed in terms of Data load mapping maintenance and to achieve another requirement.