Increase the text limit in additional information (custom fields)

In the additional information field, we have custom fields that will send an e-mail to other's to notify them of the request and what needs to be done however there is a text limit of 75 characters. Some of our events have a detailed list of things that will need to be done that we'd prefer not to write in the notes field. For example: Custodial field for a large event such as a concert. I'm unable to type out all the instructions for set up as the field only allows 75 characters. Please increase the allowed amount of text in these custom fields. Thanks!