I am not an attorney and this is just my personal opinion but I believe that the propounding party should prepare and serve an initial meet and confer letter and then wait a few days before contacting the responding party or their counsel by telephone if possible and remind them that their discovery responses are now overdue and they need to respond right away.
Accordingly, I request that your clients submit verified responses to my form and special interrogatories, requests for production of documents, and requests for admission, without objections, within 10 days from the date of this letter.
When imposing sanctions, the court shall describe the conduct.
Rule 2-402 g , that rule does not address the production of materials provided to expert witnesses.