Einstein Lead Scoring in Salesforce allows admins to customize scoring models by including or excluding specific fields that contribute to the scoring algorithm. To ensure that a particular custom field on the Lead object is excluded from the scoring model, the consultant should omit the field from the Scoring Model configuration. This ensures that Einstein Lead Scoring will not consider that field when generating lead scores, which aligns with the sales director's request to exclude it from the scoring criteria.
For more details on configuring Einstein Lead Scoring models, you can refer to the Salesforce documentation:
Einstein Lead Scoring Setup.