Release billing proposals app: Sort by note field

Hi, We need to sort by "note" field in the app "Release billing proposals". But this field is the few fields that doens´t allow to sort. So we need any field that allows by filling with text as the Note field but also allows sorting by that field. For example "overtime category" field ( in this case this field does not help us because it is necessary to activate a functionality that we are not going to use) If anyone knows of a field that could be used for this purpose we would appreciate it. Thank you in advance. Best regards